LIBRARY OF CONGRESS, 







Shelf £V? 



UNITED STATES OF AMERICA. 




A TREATISE 



ON 



PHARMACY 



FOR 



STUDENTS AND PHARMACISTS. 



\S 



BY 



CHARLES CASPARI, Jr., Ph.G., 

PROFESSOR OF THE THEORY AND PRACTICE OF PHARMACY IN THE MARYLAND COLLEGE 

OF PHARMACY. 



WITH 288 ILLUSTRATIONS. 




&M* 



PHILADELPHIA: 
LEA BROTHERS & CO. 

189 5. 



*y\ 






Entered according to the Act of Congress, in the year 1895, by 

LEA BROTHERS & CO., 
In the Office of the Librarian of Congress. All rights reserved. 



PHILADELPHIA : 
DOR NAN, PRINTER. 



PREFACE. 



The motive for writing this book was, in the main, to supply 
students of pharmacy with a text-book which, while sufficiently 
comprehensive to serve as a trustworthy guide, should be devoid of 
all unnecessary material, such as official aud unofficial formulas, etc., 
readily accessible in the Pharmacopoeia aud such books of reference 
as are usually found in drug-stores. The author was repeatedly 
assured by the late Professor Maisch, and other friends, that such a 
book was desirable, and, at their request, the task was undertaken. 
Owing to unavoidable interruptions caused by increased duties, the 
work, begun in the spring of 1894, was not completed until the 
autumn of 1895. 

Since the present advanced state of professional pharmacy is the 
fruit of long-continued labors of many competent men in both this 
country and Europe, no hesitation was had in utilizing their results, 
the author having, in fact, felt it to be his duty to incorporate with 
his own experience, extending over twenty-five years of a busy life 
as a practical pharmacist, the many valuable hints obtainable from 
numerous well-known writings. Grateful acknowledgment is hereby 
made for aid derived from such books as Proceedings of the American 
Pharmaceutical Association, The Art of Dispensing, Proctor's Lec- 
tures on Practical Pharmacy, American Journal of Pharmacy, Ernst 
Schmidt's Lehrbuch der Pharmaceutischen Chemie, Hager, Fischer 
u. Hartwich's Commentar zum Arzneibuch fur das Deutsche Reich, 
Hager's Technih der Pharmaceutischen Receptur, Die Schule der 
Pharmacie, Fliickiger's Pharmaceutische Chemie, Bornemann's Die 
Fetten und Fluchtigen Oele, and others. 



VI 



PREFACE. 



The subjects treated in this book have been grouped under three 
distinct headings. 

Part I. comprises General Pharmacy, which includes the study of 
weights and measures, specific gravity, the application and control 
of heat, mechanical subdivision of drugs, and methods of solution 
and separation, together with a classification and description of the 
various plant-products and solvents used in pharmacy. 

Part II. treats of Practical Pharmacy. This involves a study of 
the official galenical preparations, together with the many operations 
of the dispensing-counter. It has been the author's aim to explain 
as clearly as possible the various processes and apparatus met with 
in this department, and to point out difficulties likely to be encoun- 
tered, as well as the remedies therefor. All suggestions made have 
been tried and verified by the author before offering them, so that 
statements made are based on actual experience. 

Part III. is devoted to Pharmaceutical Chemistry, the study of 
which is of paramount importance to every pharmacist. While the 
subject is a very comprehensive one, and undoubtedly entitled to an 
extensive treatise, it has been confined, in this work, to such com- 
pounds as are either officially recognized in the United States Phar- 
macopoeia, or are of special interest to pharmacists. 

By a careful analysis of the working formulas of the Pharma- 
copoeia it has been thought possible to render that excellent book 
more useful to students as well as pharmacists in general. The 
Pharmacopoeia contains a number of valuable tests and assay methods 
which are unintelligible to the average reader, but which can be 
made available and interesting by a series of explanations. As such 
explanations have thus far not been offered in any of the treatises 
on pharmacy iu the English language, the attempt has been made 
to supply this want. 

This book is pre-eminently intended to be one of instruction and 
an aid in the study and use of the Pharmacopoeia. The object con- 
stantly in view was to answer, if possible, the many questions of 
why and wherefore with which students and practising pharmacists 



PREFACE. vii 

are almost daily confronted. To what extent the writer has been 
successful in this direction must be left to the judgment of the 
pharmaceutical profession. He is fully aware that imperfections 
must of necessity exist in a work covering so extended a field of 
study, and he hopes that those better able to judge will kindly 
inform him of any apparent or real defects, so that they may be rec- 
tified in a subsequent edition, should such ever be demanded. 

The author desires to express his warmest acknowledgments to 
his friends, A. D. Clark aud J. P. Piquett, for valuable sugges- 
tions and aid in proof-reading, to all parties who kindly furnished 
drawings and electros for purposes of illustration, and to the pub- 
lishers who have spared neither expense nor labor to bring the 
typography, engravings, and general outfit of the book up to the 
fullest requirements. 

CHARLES CASPARI, Jr. 

Baltimore, September, 1895. 



CONTENTS 



PART I. 

GENERAL PHARMACY. 
CHAPTER I. 

PAGE 

Pharmacopoeias 17 

History. Arrangement. Nomenclature. Dispensatories. 

CHAPTER II. 

Weights and Measures .... 24 

History. Avoirdupois Weight. Apothecaries' Weight. Fluid Measure. 
Metric System. The Balance. Weights. Measures. Graduates. Pipettes. 
Approximate Measurements. 

CHAPTER HI. 

Specific Gravity 45 

Of Liquids. Specific Gravity Bottles. Specific Gravity Balance. Hy- 
drometers. Alcoholometer. Of Solids. Specific Volume. Adjustment of 
Specific Gravity and Percentages. 

CHAPTER IV. 

Heat 70 

Sources of Heat. Apparatus for Generating Heat. Apparatus for Regu- 
lating Heat. Apparatus for Measuring Heat. Boiling-point. Melting- 
point. 

CHAPTER V. 

Collection and Preservation of Crude Drugs . 91 

CHAPTER VI. 
Mechanical Subdivision of Drugs ... 94 

Grinding of Drugs. Drug-mills. Sifting. Trituration. Levigation. 
Elutriation. Precipitation. Reduction. Granulation. 



x CONTENTS. 

CHAPTER VII. 

PAGE 

Solution 108 

Simple Solution. Complex Solution. Determination of Solubility. Satu- 
rated Solution. Supersaturated Solution. Percentage Solutiou. Solvents. 
Lixiviation. Infusion. Decoction. Maceration. Digestion. 

CHAPTER VIII. 

Percolation 117 

History. Principle. Apparatus. Management. Repercolation. Continu- 
ous percolation. 

CHAPTER IX. 
Separation of Non-volatile Matter . .132 

Filtration. Straining. Filters and Funnels. Filter-pumps. Filtering 
Media. Separators. Decantation. Clarification. Decoloration. Expres- 
sion. Dialysis. 

CHAPTER X. 

Separation of Volatile Matter . . . 154 

Evaporation. Direct. In Vacuo. Spontaneous. Mechanical Stirrer. 
Desiccation. Incineration. Calcination. Torre faction. Distillation. Stills. 
Condenser. Fractional Distillation. Destructive Distillation. Sublimation. 

CHAPTER XL 
Crystallization 176 

Classification of Crystals. Water of Crystallization. Interstitial Water. 
Efflorescence. Deliquescence. Mother-liquor. 

CHAPTER XII. 
Classification of Natural Products Used in Pharmacy. 185 

Gums. Resins. Oleoresins. Gumresins. Balsams. Fats. Fixed Oils. 
Volatile Oils. 



PAET II. 

PRACTICAL PHARMACY. 

CHAPTER XIII. 
The Official Waters .... 206 



CONTENTS. xi 

CHAPTER XIV. 

PAGE 

The Official Solutions or Liquors . . .211 

CHAPTER XV. 
Decoctions and Infusions .... 213 
Official Decoctions. Official Infusions. 

CHAPTER XVI. 

Syrups 218 

Official Syrups. Flavoring Syrups, Medicated Syrups. 

CHAPTER XVII. 
Mucilages, Honeys, and Glycerites . . . 229 

CHAPTER XVIII. 

Elixirs 233 

CHAPTER XIX. 

Spirits or Essences 238 

CHAPTER XX. 

Tinctures 241 

Classification of Official Tinctures. 

CHAPTER XXL 
Wines and Vinegars .... 251 
Official Wines. Official Vinegars. 

CHAPTER XXII. 

Fluid Extracts 255 

History. Official Process of Manufacture. Classification. 

CHAPTER XXIII. 

Extracts 265 

Consistence. Aqueous Extracts- Alcoholic Extracts. Hydroalcoholic 
Extracts. Changes by Evaporation. Official Extracts. 

CHAPTER XXIV. 
Oleoresins.and Resins .... 278 
Official Oleoresins. Official Resins. 



xii CONTENTS. 

CHAPTEE XXV. 

PAGE 

Collodions 284 

CHAPTER XXVI. 

Emulsions 286 

Official Emulsions. 

CHAPTER XXVII. 

Mixtures 295 

Pharmaceutical Incompatibility. Chemical Incompatibility. Therapeut- 
ical Incompatibility. Summary of Incompatibles. Official Mixtures. 

CHAPTER XXVIII. 

Pills 308 

Pill-masses. Excipients. Division of Pill-masses. Pill-rolling. Pill- 
dusting. Pill-coating. Official Pills. Official Masses. 

CHAPTER XXIX. 
Confections and Lozenges .... 335 
Official Confections. Apparatus for making Lozenges. Official Lozenges. 

CHAPTER XXX. 
Compressed Tablets and Tablet Triturates . . 344 
Hypodermic Tablets. Tablet Saturates. 

CHAPTER XXXI. 

Powders 354 

Mixing of Powders. Division of Powders. Powder-dividers. Apparatus 
for filling Powders into Capsules. Cachets. Official Compound Powders. 
Official Triturations. Oil Sugars. 

CHAPTER XXXII. 
Granular Effervescent Salts . . . 366 
Official Effervescent Salts. 

CHAPTER XXXIII. 
Ointments and Cerates .... 370 
Preparation and Preservation. Official Ointments. Official Cerates. 



CONTENTS. xiii 

CHAPTER XXXIV. 

PAGE 

Liniments and Oleates .... 380 

Official Liniments. Normal Oleates. Official Oleates. Ointments of 
Oleates. 

CHAPTER XXXV. 

Plasters and Suppositories .... 385 

Preparation of Plasters. Spreading of Plasters. Official Plasters. Prepa- 
ration of Suppositories. Suppository Moulds. Compressors. Machines. 
Bougie Moulds. Suppository Shells. Glycerin Suppositories. 



PART III. 
PHARMACEUTICAL CHEMISTRY. 

Inorganic Substances. 

CHAPTER XXXVI. 
Hydrogen and Oxygen .... 405 

CHAPTER XXXVII. 
Chlorine, Bromine, and Iodine . . . 408 

CHAPTER XXXVIII. 
Sulphur, Phosphorus, Carbon, and Boron . . 414 

CHAPTER XXXIX. 

The Inorganic Acids .... 417 

CHAPTER XL. 

The Compounds of Potassium . . . 429 

CHAPTER XLI. 
The Compounds of Sodium .... 443 

CHAPTER XLII. 
The Compounds of Lithium .... 458 



xiv CONTENTS. 

CHAPTER XLIII. 

PAGE 

The Compounds of Ammonium . . . 461 

CHAPTER XLIV. 
The Compounds of Barium, Calcium, and Strontium . 469 

CHAPTER XLV. 

The Compounds of Magnesium . . . 478 

CHAPTER XLVI. 
The Compounds of Aluminum and Cerium . . 482 

CHAPTER XLVII. 
The Compounds of Iron .... 486 

CHAPTER XLVIII. 
The Compounds of Manganese and Chromium . .511 

CHAPTER XLIX. 
The Compounds of Mercury .... 513 

CHAPTER L. 
The Compounds of Antimony, Arsenic, and Bismuth . 522 

CHAPTER LI. 
The Compounds of Copper, Lead, Zinc, Gold, and Silver 533 

Organic Substances. 

CHAPTER LII. 
Cellulose and Its Derivatives . . . 546 

CHAPTER LIII. 
The Derivatives of Coal Tar . . . 555 
CHAPTER LIV. 

Starches, Gums, and Sugars . . . 561 

CHAPTER LV. 
Alcohol and its Derivatives . . . 571 



CONTENTS. xv 

CHAPTER LVI. 

PAGE 

Fats and Fixed Oils .... 588 

CHAPTER LVII. 
Volatile Oils and Resins .... 597 

CHAPTER LVIII. 
Organic Acids 607 

CHAPTER LIX. 

Alkaloids . . . . . . 619 

CHAPTER LX. 
Neutral Principles and Glycosides . . . 645 

CHAPTER LXr. 
Animal Ferments 649 



PART I. 

GENERAL PHARMACY. 

CHAPTEE I. 

PHAEMACOPCEIAS. 

Although the term Pharmacopoeia (from the Greek (p&p/uanov, 
medicine, and xoieiv, to make) is defined by lexicographers as mean- 
ing a book of formulas or directions for the preparation of medi- 
cines, the word has now received a more liberal construction and is 
taken to include, besides the foregoing, also descriptions of vegetable 
as well as mineral and animal drugs, together with appropriate 
tests for establishing the identity and quality of the same, the whole 
prepared by some recognized authority. 

The necessity for a definite and authoritative standard in the selec- 
tion and preparation of medicines was long since recognized by all 
civilized nations, thus the Loudon Pharmacopoeia was established in 
1618, that of Paris in 1639 and that of Edinburgh in 1699. The 
first truly national staudard was that of France, issued in 1818, 
which retained the name of its predecessor, the Paris Pharmacopoeia, 
and is even to-day still known as the Codex Medicamentarius. The 
first United States Pharmacopoeia was established in 1820, prior to 
which time various foreign pharmacopoeias had been in use in this 
country. The British Pharmacopoeia, into which were merged the 
London, Edinburgh and Dublin (established 1807) Pharmacopoeias, 
was first issued in 1864, while Germany did not adopt a national 
standard until 1872, nearly two years after the restoration of the 
German empire. Owing to the rapid advances in the science of 
medicine and pharmacy, frequent revisions have become necessary, 
and the following table shows the date of the last revised editions of 
the pharmacopoeias of leading nations : 

Country. Date of Issue. Country. Date of Issue. 

Germany (supplement) . 1895 Russia .... 1891 



France (supplement) 

The United States 

Denmark 

Switzerland 

Italy 

Japan 



1895 Germany .... 1890 

1893 Great Britain (supplement) 1890 

1893 Austria .... 1889 

1893 Great Britain . . . 1885 

1892 France . . . .1884 

1891 Spain .... 1884 



The Pharmacopoeia of the United States, although without the 
power of legal enforcement by act of Government, is, nevertheless, 

2 



18 GENERAL PHARMACY. 

recognized as an authority by the courts, and is the standard em- 
ployed in the purchase of medical supplies for the Army and Navy 
of the United States. In some of the States it has been adopted as 
the legal standard in the enforcement of pharmacy laws, and this 
plan is likely to be followed by others. The Pharmacopoeia as now 
published represents the joint work of the medical and pharmaceutical 
professions ; but in the early part of this century, when pharmacy 
had not yet reached the state of a fully developed profession in this 
country, the apothecary held a rather subordinate positiou, aud 
therefore had no voice in the compilation of the first national 
Pharmacopoeia, which was adopted in 1820 by a convention of 
physicians assembled at Washington, D. C, under the presidency of 
Dr. S. L. Mitchell, the publication of the book being entrusted to a 
special committee of which Dr. Lyman Spalding was chairman, and 
both the Latin and English languages being used in the text. In 1830, 
through some misunderstanding and consequent dissatisfaction, two 
separate conventions were held for the revision of the Pharmacopoeia, 
one in New York and one in Washington, and at the latter the 
Government medical service was represented for the first time and 
participated in the proceedings; at this time provision was also 
made for regular subsequent revisions every ten years. In the 
Pharmacopoeia of 1840 the Latin version of the text was omitted, 
and in this revision material aid was also given by the pharmacists, 
although they had no representation in the convention ; numerous 
improvements in the working formulas appear in this edition. In 
the convention of 1850 two colleges of pharmacy were duly repre- 
sented by delegates, and from this time forward the value of phar- 
maceutical collaboration has been recognized, and its influence is 
discernible in the many practical details of the Pharmacopoeia. 
Since 1850 the convention for the revision of the Pharmacopoeia 
has assembled in the city of Washington, D. C, regularly in the 
month of May of every tenth year ; all duly incorporated medical 
and pharmaceutical societies and colleges throughout the United 
States are entitled to representation by three delegates, the three 
branches of the Government medical service being also represented 
by one delegate each. The final revision and publication of the 
Pharmacopoeia, under instructions from the convention, is entrusted 
to a committee of twenty-five members; this committee in 1880 
and again in 1890 was composed of twelve physicians and thirteen 
pharmacists, under the chairmanship of Charles Pice, Ph.D. 

As the Pharmacopoeia is in almost daily use by the pharmacist, a 
short study of its plan and arrangement is desirable for a more 
intelligent understanding of the text. The titles of all drugs recog- 
nized in the Pharmacopoeia, whether derived from the vegetable, 
mineral, or animal kingdom, are conveniently given in three 
subdivisions known as the official Latin name, the official English 
name, and the official definition, to which is added an official descrip- 
tion, by means of which the identity of all official substances can be 



PHAB3IA COPCEIAS. 



19 



readily established. The following examples will better illustrate 
the arrangement of pharmaeopoeial subjects : 



ACONITUM 
Aconite 
The tuber of Aeoniium Napellus, Linne (nat. ord. 



(Official Latin Name.) 
(Official English Name.) 
1 (Official Definition.) 



Banimmlaeece) 

From 10 to 20 Mm. thick at the crown ; conically "] 
contracted below; from 50 to 75 Mm long, with scars 
or fragments of radicles; dark brown externally; | 

whitish internally; with a rather thick bark, the cen- \ (Official Description.) 
tral axis about seven-rayed ; without odor ; taste at 
first sweetish, soon becoming acrid, and producing a | 
sensation of tingling and numbness, which lasts for J 
some time. 



CANTHARIS 

Caxthabides 

Qmtharis vesicatoria, De Geer (class Inseeta; order ) 
Coleoptera) j 

About 25 Mm. long and 6 Mm. broad ; fiattish-cylin- ] 
drical, with filiform antennae, black in the upper part, 
and with long wing-cases, and ample membranous, | 
transparent, brownish wings ; elsewhere of a shining )- 
coppery-green color. The powder is grayish-brown, 
and contains green, shining particles. Odor strong and | 
disagreeable; taste slight, afterwards acrid. 



(Official Latin Name.) 
(Official English Name.) 
(Official Definition. 



(Official Description.' 



PLUMBI CARBON AS 

Lead Carbonate 
2PbCO s .Pb(OH) a = 772.82 

A heavy, white, opaque powder, or a pulverulent 
mass, without odor or taste Permanent in the air. 
Insoluble in water or alcohol, but soluble in acetic or 
diluted nitric acid with effervescence. When strongly 
heated, the salt turns yellow without charring, and if 
heated in contact with charcoal, it is reduced to metal- 
lic lead. Its solution in diluted nitric acid yields a 
black precipitate with hydrogen sulphide, a yellow one 
with potassium iodide, and a white one with diluted 
sulphuric acid. One Gm. of the salt strongly ignited 
in a porcelain crucible, should leave a residue of lead 
oxide weighing not less than 085 Gm. 



(Official Latin Name.) 
(Official English Name.) 
(Official Definition. 



(Official Description.) 



The Official Latin Name, which very properly is given in the 
Latin language, owing to its security against change, is intended to 
be at once simple and distinctive, and must be accepted as repre- 
senting the drug or preparation more particularly defined in the 
other subdivisions. In some instances the names by which drugs 
have been long known have been retained without any special 
reference to the source, thus Galla, Buchu, Cusso, Opium, Mastkhe, 
Senna, Kino, Kamala, etc., but in the majority of cases the generic 
or specific name of the plant or aniihal yielding the drug has been 
adopted as the official name, thus Aconitum, Camphora, Catechu, 



20 GENERAL PHARMACY. 

Ipecacuanha, Coccus. Hyoscyamus, Moschus, Rheum, Senega, etc. 
In order to avoid confusion a few of the former generic or specific 
names of plants have been retained as the official names of drugs 
now known to be derived from a different source, as in the case of 
Quassia from Picrcena excelsa, Cambogia from Garcinia Hanburii, 
Pareira from Chondodendron tomentosum, etc. 

As different species of the same genus often furnish different 
drugs, it becomes necessary in such cases either to employ the full 
botanical name of the plant to distinguish the official varieties, as 
Viburnum opulus and Viburnum prunifolium, Rosa centifolia. and 
Rosa gallica, or to select the generic name only for one of the drugs 
and the full botanical name for others, as in the case of the genus 
Rubus, where the Pharmacopoeia has chosen the generic name of the 
plant, Rubus villosus, to designate the root of the blackberry, but the 
full name of the plant, Rubus ida3us, as the official name for the fruit 
of the raspberry. 

Whenever different parts of the same plant are officially recog- 
nized as distinct drugs, the name of the particular part must be 
added to the generic or specific name of the plant, thus Arnicce 
Flores and Arnicoe Radix, Belladonnas Folia and Belladonnas Radix, 
etc.; to this rule the Pharmacopoeia makes an exception in the case of 
Sassafras bark and pith, both derived from Sassafras variifolium — 
the bark is officially known by the generic name only, while the 
pith is designated as Sassafras Medulla. 

In the official names of compound preparations the principal 
active constituents are as a rule specified, as Liquor Ferri et Am- 
monii Acetatis, Tinctura Aloes et Myrrhaz, Trochisci Glycyrrhizo?- et 
Opii, Piluloe Aloes et Ferri, Mistura Rhei et Sodas, but usage has 
sanctioned a modification of this rule when there are many ingre- 
dients, by naming one of them with the addition of an adjective, 
such as compositus, a, um (compound), aromaticus, a, um (aromatic), 
etc., thus making a simple comprehensive title, as Spiritus Am- 
monia? Aromaticus, Tinctura Cinchonas Composita, Pilulos Catharticoe 
Vegetabiles, Pidvis Morphinaz Compositus, Linimentum Sinapis Com- 
positum, etc. 

In the case of chemical compounds where similar combinations of 
the same elements, or several varieties of the same compound, have 
received recognition, it is absolutely necessary that the official name 
include some qualifying term by means of which the character of 
the substance may at once be recognized, thus FLydrargyri Chlori- 
dum — Corrosivum and Mite, Hydrargyri Iodidum — Flavum and 
Rubrum, Ferri Sulphas — Exsiccatus and Granulatus, etc. 

The Latin official names are generally used in the singular num- 
ber, even though the idea of plurality may be essentially connected 
with the drug, as in the case of Caryophyllus, Galla, Amygdala, 
Pilocarpus, etc. ; this is in accordance with the precedent set by the 
Roman medical writers. Whenever a part of the plant also appears 
in the official name the following rule prevails : Semen (seed), Cortex 



PHARMACOPEIAS. 21 

(bark), Radix (root) are always used in the singular, while Folia 
(leaves) and Fiores (flowers) are invariably used in the plural. 

The Official English Name need not necessarily be a literal 
translation of the official Latin name, in fact it seems very desirable 
that a drug should have two distinct names officially recognized, the 
one confined to the official Latin title, admirably adapted to abbrevia- 
tion and use in prescriptions, while the other may be employed in 
the ordinary course of conversation and is intended for use in com- 
mercial transactions and the daily routine of business, as Nutmeg for 
Myristica, Brandy for Spiritus Vini Gallici, Black Haw for Vibur- 
num Prunifolium, Pale Rose for Rosa Centifolia, Cascara Sagrada 
for Rhamnus Purshiana, Pumpkin Seed for Pepo, etc. Occasionally 
the English name is used in the plural while the Latin name is 
always used in the singular number, as Cantharides for Cantharis, 
Cloves for Caryophyllus. In the case of chemical compounds the 
official English name often indicates with greater precision the true 
composition, as Solution of Mercuric Nitrate for Liquor Hydrargyri 
Nitratis, Ferrous Sulphate for Ferri Sulphas, Ferric Citrate for Ferri 
Citras, etc. 

In a large number of instances a second English name, which long 
custom has demanded shall not be ignored, is given as a synonym 
in the title, although its origin may be unscientific and its reten- 
tion not in strict accord with the systematic nomenclature of the 
Pharmacopoeia; the synonym invariably follows the official English 
name and is enclosed in brackets. Among the prominent synonyms 
found in the Pharmacopoeia are Calomel for Mild Mercurous Chloride, 
Epsom Salt for Magnesium Sulphate, Balm for Melissa, Labarraque's 
Solution for Solution of Chlorinated Soda, Witch-hazel for Hamamelis, 
Sweet Flag for Calamus, Black Draught for Compound Infusion of 
Senna, Red Precipitate for Red Mercuric Oxide, Griffith's Mixture 
for Compound Iron Mixture, Tully's Poivder for Compound Powder 
of Morphine, Citrine Ointment for Ointment of Mercunc Nitrate, 
Basilicon Ointment for Resin Cerate, etc. 

Several of the official synonyms have been added for the purpose 
of more clearly expressing the true chemical character of the com- 
pounds for which they are used, than is possible with the official 
Latin or English names, as Phenylacetamide for Acetanilid, Sodium 
Paraphenolsidphonate for Sodium Sulphocarbolate , Phenyl Salicylate 
for Salol, Beta NapJdol for Naphtol, etc. 

The Official Definition determines the source and character ot 
the drug or chemical as recognized by the Pharmacopoeia. In the 
case of vegetable drugs the botanical name of the plant yielding the 
drug is composed of two parts, the generic name and the specific 
name, always written in the same order of sequence ; the first or 
generic name is invariably begun with a capital letter, and is usually 
employed as the official Latin name of the drug, while the specific 
name is only begun with a capital letter when derived from a generic 
name, as in Cytisus Scoparius, or from a proper name, as in Garcinia 



22 GENERAL PHARMACY. 

Hanburii, or when it is indeclinable, as in Aspidosperma Quebracho- 
bianco. The necessity for nsing the full botanical name of the 
plant to indicate the source of the official drug is clearly shown in 
the case of the genus Lobelia, of which the Pharmacopoeia recognizes 
only the species inflata, although two others, syphilitica and cardi- 
rialis, are also well known ; of the genus Grindelia two species, 
robusta and squarrosa, are recognized as furnishing the official drug. 
Accompanying the botanical name of the plant is the name of the 
author, printed in Roman type, and following it, enclosed in paren- 
theses, the natural order to which the plant belongs, thus, Veronica 
virginica, Linne (nat. ord. Scrophulariaceai). 

In the case of official chemicals it becomes necessary to establish 
the identity of the compound by expressing its exact composition 
by means of symbolic formulas ; thus in the case of sodium phos- 
phate the formula Xa 2 HP0 4 + 12H 2 specifies clearly the kind 
officially recognized bv that name; other varieties of sodium phos- 
phate, such as Na 2 HP0 4 +6H 2 0, Na 2 HP0 4 , or even NaH 2 P0 4 , or 
Na 3 P0 4 can therefore not be used in prescriptions or official prepara- 
tions. The official definition of alumen, alum, is Al 2 K 2 (S0 4 ) 4 -f- 
24H 2 0, showing that the pharmacopoeia! alum is potassium alum, 
or, more strictly speaking, potassium and aluminum sulphate; since 
commercial alum, as a rule, is ammonium alum, the official definition 
is important, and necessary to establish the chemical character of 
the compound to be used as alum in prescriptions and official 
preparations. The Pharmacopoeia recognizes as magnesium car- 
bonate a compound for which the symbolic formula 4MgC0 3 .Mg 
(OH) 2 -}-5H 2 is given, which shows it to be not true magnesium 
carbonate, but a substance containing four molecules of magnesium 
carbonate, one molecule of magnesium hydroxide, and five molecules 
of water. The official definition for pure morphine, C 17 H 19 N0 3 + 
H 2 0, recognizes a compound containing one molecule (in this case 
5.94 per cent.) of water, and for pure quinine C^H.^^Og + 3H 2 0, 
a compound containing three molecules (in this case 14.28 per cent.) 
of water. Whenever water is expressed in a symbolic formula, as 
in the five cases above mentioned, it forms an integral part of that 
formula, and is shown to be an essential constituent of the official 
compound ; in the majority of cases the presence of such water lends 
to the compound its power to assume the crystalline form, and is 
then known as water of crystallization, but when not so required it 
is known as water of hydration, as in the case of the official magne- 
sium carbonate. Every symbolic formula is followed by a number 
which expresses the molecular weight of the compound, that is, the 
sum of the weights of the atoms of component elements ; thus in 
the case of the official bismuth citrate, BiC 6 H 5 7 = 397.44, the 
molecular weight 397.44 is equal to the sum of the weights of all 
the atoms represented in the compound, namely, 1 atom of bismuth 
= 208.9, 6 atoms of carbon = (11.97 X 6) 71.82, 5 atoms of hydro- 
gen = (1 X 5) 5, and 7 atoms of oxygen = (15.96 X 7) 111.72, 



PHARMA COPCEIAS. 23 

or 208.9 + 71.82 + 5 + 111.72 = 397.44 ; official sodium carbonate 
is given as Xa 2 C0 3 + 10H 2 O = 285.45, in which case the weight of 
all the atoms of the crystalline compound, including the water, is 
accounted for in the molecular weight, 285.45, as follows : 2 atoms 
of sodium = 23 X 2 or 46, 1 atom of carbon = 11.97, 3 atoms of 
oxygen = 15.96 X 3 or 47.88, ten times 2, or 20 atoms of hydro- 
gen = 1 X 20 or 20, and 10 further atoms of oxygen = 15.96 X 10 
or 159.6, or 46 + 11.97 + 47.88 + 20 + 159.6 = 285.45. 

The number following simple elements expresses only the weight 
of a single atom, as bromine, Br = 79.76, sulphur, S = 31.98, 
etc. Atomic and molecular weights are of value in the proper 
construction of equatious for the purpose of demonstrating chemical 
reactions. 

The Official Description. While the official definition is a brief 
but exact statement of the nature and source of drugs and of the 
composition of chemicals, the official description amplifies the defini- 
tion by adding the physical characteristics of drugs, such as shape, 
size, odor, and taste, together with a statement of possible impuri- 
ties and adulterations and means for their detection. For chemicals 
is added a clear account of their physical properties, their behavior 
toward different solvents, and such tests as shall enable the phar- 
macist to detect impurities and establish the fulfilment of pharma- 
copceial requirements. The official description is always printed in 
small type, and forms a most valuable and important part of the 
Pharmacopoeia. 

Dispensatories. 

A dispensatory is a commentary on the Pharmacopoeia, and, as 
such, has become indispensable to both physicians and pharmacists. 
While the text of the Pharmacopoeia is coufined to the definition aud 
description of drugs and chemicals as well as to the official tests and 
requirements and accepted formulas for numerous preparations, much 
valuable additional information is given in the dispensatories, such 
as historical data, action, and uses, as well as doses of medicines, 
together with comments on and explanations of pharmaceutical and 
chemical processes. Besides the official drugs and chemicals, a large 
number of unofficial remedies aud formulas are also treated in detail. 
Two dispensatories are published in this country : the United States 
Dispensatory, established in 1833, by Wood and Bache, which has 
now reached its seventeenth edition, and the National Dispensatory, 
established in 1879, by Stille and Maisch, of which five editions 
have thus far been published. 



CHAPTER II. • 

WEIGHTS AND MEASURES. 

Meteology (from the Greek word ptTpov, measure, and Uyog, a 
discourse) is a study of the art and science of measurements as 
applied to extension, volume, and weight of matter. Measure of 
extension may be either of length or of surface, while measure of 
volume or bulk applies to the cubic contents. Measure of weight 
is the determination of the gravitating force of bodies, that is, of 
their attraction by the earth toward its centre, such attraction bearing 
a direct relation to the quantity of matter contained in a body ; 
hence weight is pressure exerted by a body upon a horizontal plane 
supporting it. True weight can only be obtained in vacuo, where 
the exact measurements of the force of gravitation cannot be inter- 
fered with by atmospheric pressure ; all measurements of weight in 
any medium, such as air or water, must therefore give low results. 
Ordinary operations of weighing, being conducted in air, give ap- 
parent weight of the substance only. 

Weighing and measuring being operations of daily occurrence in 
pharmacy which require care and exactness, a knowledge of the 
standards of weights and measures in use in this country and else- 
where is absolutely necessary. With more or less modification the 
standards at present in use in pharmacy in the United States and 
Great Britain are the same as those formerly employed by the 
Romans, and which in all probability were by them derived from 
the more ancient Greek nation. Three different systems of weights 
are at present employed in all English-speaking nations ; namely, 
avoirdupois weight, apothecaries' weight aud metric weight. 

Avoirdupois weight, as its name would seem to indicate, is prob- 
ably of French origin (avoir du poids, to have weight), and was no 
doubt introduced into Great Britain during the reign of the Nor- 
man dynasty; it first appeared in the English statute-books in 1335. 
Avoirdupois weight is employed in the sale of all commodities ex- 
cept precious metals and precious stones, hence drugs are always 
bought and sold by pharmacists by this system. In Great Britain 
avoirdupois weight is also employed in the formulas of the British 
Pharmacopoeia, and is now known there under the name of Imperial 
weight. In 1824, the value of an avoirdupois pound was defined 
by law in England to be f $%$■ of the old standard troy pound. The 
divisions of avoirdupois weight are the pound, ounce, drachm, and 
grain, which are symbolized by the followiug characters : ft), oz., 



WEIGHTS AND MEASURES. 25 

drni., gr.; each pound contains 16 ounces and each ounce 16 drachms 
or 437J grains. The term drachm is rarely employed, quantities 
less than an ounce being usually designated by common fractions, 
such as -fa oz., J oz., \ oz., or in grains. The avoirdupois pound 
containing 7000 grains (437J X 16) is the only pound used in the 
United States and Great Britain except at the mints ; the standard 
pound is the equivalent in weight of 27.7015 cubic inches of distilled 
water at 62° Fahrenheit and normal barometric pressure. 

Apothecaries' weight was probably derived from troy weight, 
which latter was introduced into Great Britain, by merchants from 
Lombardy, toward the close of the thirteenth century ; it is em- 
ployed altogether in the writing and compounding of physicians' 
prescriptions, and is divided into grains, scruples, drachms, and 
ounces, of which 20 grains are equal to 1 scruple, 3 scruples are 
equal to 1 drachm, and 8 drachms are equal to 1 ouuce. The 
apothecaries' ounce is of the same value as the now obsolete English 
troy ounce. The following symbols are employed to designate the 
divisions of apothecaries' weight, and always precede the number 
indicating the quantity intended, which is expressed in Roman 
numericals, thus, gr. j, for one grain, 3ij, for two scruples, 5"j, for 
three drachms, §iv, for four ounces. As far back as 1266, during 
the reign of Henry III., a statute was enacted in England which 
provided that an English silver penny, called a sterling, round and 
without clipping, should equal in weight 32 wheat-grains, well dried 
and taken from the centre of the ear, and that of such pence 20 
should make 1 ounce, and 12 ounces 1 pound. About 1497, in the 
time of Henry VII., the weight of the silver penny, however, was 
changed to the equivalent of 24 wheat-grains. These statutes clearly 
indicate the origin of the pennyweight and the troy system, from 
which the apothecaries' weight, still in use at the present day, was 
subsequently derived. The choice of wheat-grains from the centre of 
the ear arose from a desire for uniformity in size and weight, as did 
likewise the directions to employ the grain well dried. The adoption 
of troy weight by physicians and pharmacists dates back to 1618, 
when the first London Pharmacopoeia was compiled. In 1826, 
Imperial measures and standards were legalized in England, and in 
1827 exact copies of these standards were furnished the minister of 
the United States Government at London ; namely, the standard 
yard, a bronze bar of 36 inches length, a brass troy-pound weight 
of 5760 grains, and a brass avoirdupois-pound weight of 7000 
grains ; copies of these standards were supplied to the different 
States in 1836 by Act of Congress. The length of the standard 
yard is determined by comparison with a pendulum beating seconds 
of mean time, in a vacuum, at the temperature of 62° Fahrenheit, 
at the level of the sea, in the latitude of London ; the length of such 
a pendulum was found to be 39.13929 inches. 

From what has been said above it is clear that every troy or 
apothecaries' ounce is heavier than the avoirdupois ounce by 42J 



26 GENERAL PHARMACY. 

grains ; hence. to find the corresponding value in avoirdupois ounces 
of any given number of troy or apothecaries' ounces, add to the 

latter -— - J _ ( —^ or __ ) of that number, thus gxxiv = 24 
43/J V875 175y 

17 

avoirdupois ounces plus - — of 24, which is 24 + 2.33, or 26.33 
175 

ounces ; if, on the other hand, avoirdupois weight is to be converted 
into apothecaries' or troy weight, subtract from the number of ounces 

421 s g5 17N 
given _— ? = ( — ^ or J of the number, thus 26.33 ounces 

= 26.33 — -il of 26.33, which is equal to 26.33 — 2.33, or 24 
iy.z 

apothecaries' or troy ounces. 

While apothecaries' weight is employed in compounding prescrip- 
tions both in this country and Great Britain, it is not used in either 
the United States or British Pharmacopoeias, and will no doubt be 
entirely abolished in the course of time, when a uniform international 
system of weights shall have been adopted by the medical and phar- 
maceutical professions of both countries. The grain is the connect- 
ing link between avoirdupois, troy, apothecaries' and Imperial weight, 
being the same in all. 

The fluid measure used by pharmacists of the United States is 
derived from the old wine measure of England (now extinct), which 
allowed to each wine gallon the volume of 231 cubic inches, or 
58340.011 grains of distilled water at 15° C. (59° P.); the Im- 
perial gallon of Great Britain contains 277.273 cubic inches, or 
70,000 grains of distilled water at 62° Fahr. In both cases the 
gallon is divided into 8 pints, but the pint of wine measure con- 
tains 16 fluidounces, while the Imperial pint contains 20 fluid- 
ounces. The United States fluid measure has the following units : 
the minim, the fluidrachm, and the fluidounce, which are repre- 
sented by the following signs : n^, f5, f§ ; in addition, the pint and 
gallon are sometimes employed in commercial transactions, being 
designated by the abbreviations O, from Octarius, for pint, Cong. y 
from Congius, for gallon. The units of Imperial fluid measure bear 
the same names as those employed for United States fluid measure, 
but differ from them in value ; thus, while the Imperial minim of 
water weighs 0.91 (0.9114583) grain, the United States minim of 
water weighs 0.95 (0.9493) grain, and, since both fluidounces contain 
480 minims, the Imperial fluidounce of water weighs 437.5 grains, 
but the United States fluidounce 455.70 grains, at 15.6° C. (60° F.). 
Each fluidounce is divided into 8 fluidrachms and each fluidrachm 
into 60 minims. 

It must not be overlooked that many liquids, although dispensed 
and sold by the apothecary by fluid measure, are purchased from the 
manufacturer by weight, and whenever the specific gravity of the 
liquid differs materially from that of water there must be also a 



WEIGHTS AND MEASURES. 27 

marked difference in the relative volume ; thus glycerin, syrups, 
chloroform, ethers, acids, essential oils, and many chemical solu- 
tions, are always purchased by weight. The following list shows the 
number of fluidounces in one pound of the respective liquids, of 
pharmacopoeial quality : 

One Pound of Sulphuric Acid measures about . . 8J fluidounces. 

" " Monsel's Solution measures about . . 10 " 

" Chloroform " " 10 : V 

" Syrup " " . .11| 

" Glycerin " " 12} 

" Goulard's Extract " " 12| 

" " Ammonia Water " " . .16 

" " Stronger Ammonia "Water measures about 17 " 

" Spirit of Nitrous Ether " " 18^ 

" Essential Oil measures from . .13 to 18 

" Ether measures about . . . . 21J- " 

The Metric or Decimal system of weights and measures, which is 
the only official system of the present United States Pharmacopoeia, 
is supposed to have originated in the fertile mind of the French 
statesman, Prince de Talleyrand, toward the close of the last cen- 
tury, and was enforced in France by law in December, 1799. It 
has already become the legal standard in all civilized countries 
except the United States and Great Britain, and is destined to 
become the universal standard for commercial transactions, as it is 
already for strictly scientific work, the world over. 

The use of metric weights and measures was legalized in the 
United States and Great Britain in 1866, but neither country has 
as yet officially adopted them, although the prospects for such desira- 
ble action are brightening. In 1878 the use of the metric system 
was made obligatory in the purchase of medical supplies for the 
United States Marine-Hospital service. Since the introduction of 
a new system of weights and measures must, no doubt, for a time 
create some confusion, a careful study of the same is required of 
pharmacists and physicians. The principles upon which the metric 
system was founded are as follows : The reduction of all weights 
and measures to one uniform standard of linear measure ; the use 
of an aliquot part of the earth's circumference as such standard; 
the application of the unit of linear measure to matter in its three 
modes of extension — length, breadth, and thickness — as a standard 
of all measures of length, surface, and solidity ; the cubic con- 
tents of linear measure in distilled water at the temperature of its 
greatest density to furnish at once the standard measure of weight 
and of capacity ; everything susceptible of being weighed or 
measured to have only one measure of weight, one measure of 
length, and one measure of capacity, with their multiples and sub- 
divisions exclusively in decimal proportions, and every weight and 
every measure to be designated by an appropriate significant char- 
acteristic name applied exclusively to itself. 

As a basis, the authors of the metric system adopted a quadrant 



28 GENERAL PHARMACY. 

(one-fourth) of the earth's circumference, and dividing this into ten 
million parts they obtained a certain measure of length, which they 
named meter (French metre) and adopted as a standard for all units 
of measurements ; this meter, which was made the unit of linear 
measure, is equal to 39.3704 inches. One-tenth part of the meter, 
applied to cubic measurement, was made the unit of measure of 
capacity and called a liter (French litre) ; it is equal to 33.8149 
U. S. fluidounces or 2.1135 wine pints. The one-thousandth part 
of the liter (which is equal to the cube of one-hundredth part of 
the meter) was chosen to furnish the unit of weight ; the w r eight 
of such a volume of distilled water at its greatest density, 4° C. 
(39.2° F.), was called a gramme, and is equal to 15.43235639 grains. 
The multiples of these units are denoted by prefixes of the Greek 
numerals, deka 10, hecto 100, kilo 1000, myria 10,000 ; while pre- 
fixes of the Latin numerals denote the subdivisions, thus deci, one- 
tenth ; centi y one-hundredth, and miU% one-thousandth. Two other 
units of the metric system, the are (the square of ten meters), and 
the stere (a cubic meter), are not of pharmaceutical interest. Al- 
though the liter is the unit of measures of capacity, the subdivisions 
of this unit are almost invariably spoken of as so many cubic cen- 
timeters, since each liter is equal to 1000 cubic centimeters, thus 
the expressions 10, 50, 100, 250, 750 cubic centimeters, etc., are 
preferred to 1 centiliter, 5 centiliters, 1 deciliter, one-fourth of a 
liter, and three-fourths of a liter. In like manner the specific names 
of the fourth multiple of the units are rarely employed, it being 
customary to designate all above the third multiple as so many of 
that multiple, thus 10 kilometers instead of 1 myriameter, 15,000 
liters instead of 1 J myrialiter, and 20 kilogrammes instead of 2 
myriagrammes, etc. When writing the names of metric measures 
and weights, abbreviations are usually employed in place of the full 
names, as will be seen from the following tables, which also give the 
corresponding values in customary weights and measures : 

Measures of Length. 

1 Myriameter, Mm. = 10000.0 M. = 6.2137 -f miles. 

1 Kilometer, Km. = 1000.0 " = 4.9710+ furlongs 

1 Hectometer, Hm. = 100.0 " = 19.8840+ rods. 

1 Dekameter, Dm. = 10.0 " = 32.8086+ feet. 

1 Meter, M. = 1.0 " = 39.3704 inches. 

1 Decimeter, dm. = 0.1 " = 3.93704 

1 Centimeter, cm. = 0.01 " = 0.393704 " 

1 Millimeter, mm. = 0.001 " = 0.0393704 " 

Measures of Capacity. 

1 Myrialiter, Ml. = 10000.0 L. = 2641.7890+ gallons. 

1 Kiloliter, Kl. = 1000.0 " = 264.1789+ " 

1 Hectoliter, HI. = 100.0 " = 26.4178+ " 

1 Dekaliter, Dl. = 10.0 " = 2.6417+ " 

1 Liter, L = 1.0 " = 33.8149+ fluidounces. 

1 Deciliter, dl. = 0.1 " = 3.38149+ 

1 Centiliter, cl. = 0.01 " = 0.338149+ " 

1 Milliliter, ml. = 0.001 " = 0.0338149+ " 

1 Cubic centimeter, ccm. = 0.001 " = 0.0338149+ " 



WEIGHTS AND MEASURES. 29 

Measures of Weight. 



1 Myriagrainme, 


Mg. 


= 


10000.0 G. = 22.0461+ pounds. 


1 Kilogramme, 


Kg- 


= 


1000.0 " = 2.2046+ 


1 Hectogramme, 


Hg. 


= 


100.0 " = 3.5273+ av. ozs. 


1 Dekagramme, 


Dg. 


= 


10.0 " = 154.3235639 grains 


1 Gramme, 


Gm. 


= 


1.0 " = 15.43235639 


1 Decigramme, 


dg. 


= 


0.1 " = 1.543235639 " 


1 Centigramme, 


eg. 


= 


0.01 " = 0.1543235639 " 


1 Milligramme, 


mg. 


= 


0.001 " = 0.01543235639 " 



The U. S. Pharmacopoeia deviates from these abbreviations 
in three instances, using Mm. in place of mm. for millimeter, 
Cm. in place of cm. for centimeter, and Cc. in place of ccm. for 
cubic centimeter. The numerical expression of all weights and 
measures should always be accompanied by the abbreviation used 
for the unit, and whenever subdivisions are not given a cipher 
should follow the decimal point, so as to indicate more clearly the 
intention of the writer ; thus, 25.0 Gm. and 350.0 Cc, leave no 
doubt whatever as to the quantities desired, whereas 25 Gm. and 
350 Cc. might have been carelessly written for 2.5 Gm. and 35.0 
Cc. Since the value of the numerical expression depends entirely 
upon the correct placing of the decimal point, due care must be 
observed, lest the misplacement thereof increase or decrease the 
intended value tenfold. When reading metric weights and measures 
the multiples of the units should be read as so many units, but the 
subdivisions are preferably named as so many of the lowest division 
possible ; for instance, 25.050 Gm. should be read 25 grammes and 
50 milligrammes instead of 25 and jfa grammes ; 0.1 25 Gm., one hun- 
dred and twenty-five milligrammes instead of 12J centigrammes or 
1 decigramme 2 centigrammes and 5 milligrammes ; 0.02 M. should 
be read as 2 centimeters or 20 millimeters, but never as y^ or 
yj-jy-o of a meter; 1.425 L. should be read as 1425 cubic centimeters 
instead of lyWo" ^er or 1 liter and 425 cubic centimeters. 

The corresponding values, in customary weights and measures, of 
a few metric weights and measures should be firmly fixed in the 
mind for convenient use while reading or studying ; as, 



1 Mm. (millimeter) = ^ of an inch. 

1 Cm. (centimeter) = § " " 

1 inch = 25 millimeters or 2} centimeters. 

1 Cc. (cubic centimeter) == 16. 23 minims or 0.27 fluidrachm or 0.0338 fluidounce. 

1 fluidounce = 29.57+ cubic centimeters at 4° C. (39.2° F.), or 29.53 Cc. at 

15.6° C (60° F.) 
1 Gm. (gramme) = 15.4324 grains. 
1 grain = 0.06479+ gramme or 64.79 milligrammes. 
1 Mg. (milligramme) = 0.01543 grain (practically ^\ grain). 
1 L. (liter) = 33.815 (nearly 34) fluidounces or 2^ pints. 

In larger commercial transactions the kilogramme is the metric 
weight generally employed, being frequently abbreviated, " kilo " ; 
it is equivalent to 2\ avoirdupois pounds -f 34 grains. 



30 



GENERAL PHARMACY. 



The following simple rules will enable anyone to readily convert 
metric weights and measures into those customary in this country, 
the results being practically correct. 

For linear measure : Divide the number of millimeters by 25, 
300, or 900 ; the quotients will be the answer in inches, feet, or 
yards, respectively. 

For measures of capacity : Divide the number of cubic centi- 
meters by 0.06163, 3.697, or 29.57 ; the quotients will be the answer 
in U. S. minims, fluidrachms or fluidounces, respectively. 

For weight: Divide the number of grammes by 0.06479, 3.8874, 
or 31.0992; the quotient will be the answer in grains, drachms, or 
apothecaries' ounces respectively. 

In the actual operations of weighing and measuring, however, 
it will be found more desirable to be provided with a set of accu- 
rate metric weights and measures ; for then even the slight errors 
arising from the translation of one system into another can be 
avoided. 



Comparative Table of Metric with Avoirdupois akd 
Apothecaries' Weights. 



Names. 


Numerical 


Equivalents in 


Equivalents in 


Equn 


•alents in 


Expressions. 


Grains. 


Avoirdupois Weight. 


Apothecaries' Weight. 




6m. 


Gr. 


lb. oz. gr. 


5 


5 gr. 


Milligramme 


0.001 


0.01543 


l 
■gl' 




i 

6? 


Centigramme 


0.010 


0.15432 


i 




£ 


Decigramme 


0.100 


1.54323 


1.5 




1.5 


Gramme 


1.0 


15.43235 


15.4 




... 15.4 


Dekagramme 


10.0 


154.32356 


... 1 45.0 




2 34.0 


Hectogramme 


1000 


1543.23563 


... 2,1 12.0 


3 


1 430 


Kilogramme 


1000.0 


15432.35639 


2 3] 10.47 


32 


1 12.4 


Myriagramme 


10000.0 


154323.56390 


22 I 14.8 


321 


4 3.5 



The weight in grains of a cubic centimeter and a U. S. minim of 
distilled water must vary with the temperature at which the meas- 
urement is made ; hence the relation between metric and U. S. 
apothecaries' fluid measure remains uniform for all temperatures. 
At 4° C. (39.2° F.) a cubic centimeter of distilled water weighs 

15.4324 grains, while a minim weighs of 456.392 grains, or 

0.9508 grain, hence each cubic centimeter is equal to 15.4324 -4- 0.9508 
or 16.23 minims ; at 15° C. (59° F.) a cubic centimeter of distilled 
water weighs 15.392 grains, while a minim weighs 0.9483 grain, 
hence each cubic centimeter is equal to 15.392 -~ 0.9483 or 16.23 
minims. 

In writing prescriptions, physicians are in the habit of considering 
4 Cc. (actually 3.6969) as equivalent to 1 fluidrachm, and 30 Cc. 
(actually 29.57) as equivalent to 1 fluidounce. 



WEIGHTS AND MEASURES. 



31 



Comparative Table or Metric and Apothecaries' Fluid Measure 



Cubic Centimeter. 


Minims. 


fs 


f5 


m 


0.06163 


1.0 








0.30815 


5.0 








0.61630 


10.0 








1.0 


16.23 








5.0 


81.15 




1 


21.15 


100 


162.30 




2 


42.3 


20.0 


324.60 




5 


24.6 


30.0 


486.90 


1 





6.9 


40.0 


649.20 


1 


2 


49.2 


50.0 


811.50 


1 


5 


31.5 


60.0 


973.80 


2 





13.8 


70.0 


1130.10 


2 


2 


56.1 


80.0 


1298.40 


2. 


5 


38.4 


90.0 


1460.70 


3 





20.7 


190.0 


1623.00 


3 


3 


3.0 


250.0 


4057.50 


8 


3 


37.5 


500.0 


811500 


16 


7 


15.0 


1000.0 


16230.00 


33 


6 


30.0 



Physicians and pharmacists cannot be too careful in the use of 
metric weights and measures in the writing and reading of prescrip- 
tions. In continental Europe, where the metric system has been in 
use for mauy years, no signs are used in prescriptions, because all 
ingredients, whether solid or liquid, are weighed, and it is under- 
stood that weight is always intended ; whenever, for any reason, 
measures are wanted, the signs L. (liter) or Ccm. (cubic centimeter) 
are employed. But in this country, and also in England, where it 
is still, and likely to remain, customary to weigh solids and to 
measure fluids in the dispensing of medicines, the official abbrevia- 
tions given in the U. S. Pharmacopoeia should be used invariably, 
so as to avoid all possible confusion ; with water, and the average 
diluted alcohol tinctures, it would probably not make much differ- 
ence whether grammes or cubic centimeters were dispensed, but in 
the case of all liquids having a higher or lower specific gravity than 
water, a marked variation will be observed ; thus 20 Gm. of glyceriu 
measure 16 Cc, and 20 Cc. of glycerin weigh 25 Gm.; 60 Gm. of 
simple syrup measure 45.5 Cc, and 60 Cc. of syrup weigh 79.02 Gm.; 
30 Gm. of chloroform measure 20.13 -f- Cc, and 30 Cc. of chloroform 
weigh 44.7 Gm.; 4 Gm. of bromoform measure only 1.4 Cc, and 
4 Cc of bromoform weigh 11.32 Gm.; 10 Gm. of ether measure 
13.77 + Cc, and 10 Cc. of ether weigh only 7.26 Gm.; 50 Gm. of 
alcohol measure 60.97 -f- Cc, and 50 Cc of alcohol weigh 41 Gm. 

It is incumbent upon the medical schools of this country to 
familiarize their students with the decimal system of weights and 
measures, as is now done in all colleges of pharmacy, and not until 
the National Medical and Pharmaceutical Associations shall have 
agreed upon some rule or guide for the two professions in the speci- 
fication of metric weights and measures in prescriptions will the 



32 GENERAL PHARMACY. 

pharmacist be relieved of annoyance and censure caused by an im- 
proper interpretation of quantities. 

In the absence of specified fluid measures it is safest to follow the 
custom of continental Europe and weigh all solids and liquids when 
dispensing prescriptions written in the metric system. 

In 1890 the United States Government obtained from the Inter- 
national Bureau of Weights and Measures prototype standards of 
the Meter and the Kilogramme, made of platinum-iridium ; these 
were placed in the custody of the Office of Standard Weights and 
Measures at Washington, and from them the commercial weights 
and measures now in use are derived. The value of the United 
States prototype standard Meter and Kilogramme is identical with 
the international standards derived from the M&tre and Kilogramme 
" des Archives " of France. 

The United States yard is defined to be equal to 36000 ° of 
J m ^ H 393700 

a meter ; the pound (avoirdupois) is denned as being equal to 

-— of a kilogramme, and the liquid gallon is the volume 

1 Q^toZoQOdv 

of 3785.434 grammes (58418.1444 grains) of w T ater at the tem- 
perature of its maximum density, weighed in vacuo. 

The instruments used in weighing and measuring are balances, 
weights, and graduated vessels, and the necessity for their accuracy 
and careful preservation cannot be too strongly emphasized. 

The Balance, or, as it is commonly called, " a pair of scales," 
is no doubt the most useful instrument in the hands of the phar- 
macist; upon its proper construction and sensitiveness depend 
the accuracy of weighing and correct dispensing of medicines ; 
hence every well-equipped pharmacy should be supplied with at 
least three balances of different quality. The general construction 
of an ordinary balance is so well known to everybody that a 
detailed description seems unnecessary ; the simple hand scales 
(see Fig. 1), which were formerly relied upon altogether, have 
almost completely disappeared in this country ; in their stead a 
more substantial instrument is now used. The single beam prin- 
ciple still prevails, in which a metallic bar is supported at its centre 
on a knife-edged axis, called the fulcrum, thus producing two arms 
of equal length. The fulcrum projects from the sides of the beam, 
and rests on two supports at the top of a stationary column, so 
constructed that the wear and tear due to constant friction is relieved 
by a special contrivance for raising the beam above the steel or 
agate plane when the balance is not in actual use. The knife- 
edged axis and the support on which it rests are both made of 
hardened steel and highly polished, in order to reduce friction to a 
minimum ; but, since even steel is liable to become rusty, particularly 
when exposed to moisture or acid vapors, agate edges and planes, 
which are practically indestructible, are now preferred on all finer 



WEIGHTS AXD MEASURES. 



33 



balances. The centre of gravity of the beam should be slightly 
below the edge of the fulcrum ; if it were in the edge of the fulcrum, 
the beam would not come to a horizontal position when the pans are 
equally loaded, but would remain in any position where it might 
chance to be placed. If it were above the edge of the fulcrum, the 
beam would remain horizontal if placed so ; but if slightly deflected it 
would tend to overturn by the action of the weight of the beam. The 
nearer the centre of gravity comes to the edge of the fulcrum, the more 



Fig. 1. 




Old-stvle hand balance. 



accurate and sensitive it will be ; but at the same time it will turn 
more slowly. The scale-pans arc suspended in suitable wire frames 
also supported by means of knife edges from the ends of the beam ; 
in order to insure perfect equilibrium it is essential that the end 
knife edges be situated equally distant from the central point of 
support and that they lie in the same plane with it, all three edges 
being parallel to each other. The lighter in weight and the more 
inflexible the beam the greater will be the sensitiveness of the 
balance. Both of these desirable qualities are obtained by the use of 
aluminum beams, which are also non-corrosive and non-magnetic. 

The scale-pans are preferably made of solid nickel or solid 
silver ; but for weighing certain chemical substances likely to attack 
the metal they should be supplanted by strong glass pans. Each 
balance is provided with an indicator in the form of a long, thin, 
flat needle attached to the centre of the beam and so arranged that 



34 



GENERAL PHARMACY 



when the beam is in perfect stable equilibrium it points directly to 
the zero mark on a short graduated plate attached to the front 
base of the upright (see Fig. 2) ; on some balances the indicator 
points upward, the graduated 
scale being placed at a little 
distance above the beam (see 
Fig. 3.). When the balance is 
in use it is far better to rely 
upon the regular, uniform oscil- 



FlG. 




Prescription balance with indicator below 
the beam. 



Prescription balance with indicator above 
the beam. 



lations of the beam as shown by the indicator on the scale than to 
await the fixed position of the indicator at the zero point. Every 
balance when purchased should be carefully tested as to its sensi- 
bility and correct adjustment ; this is best done by allowing the 
beam to oscillate freely supported on its fulcrum, with the pans 
detached. The oscillations should be regular and the beam finally 
return to its horizontal position of rest ; but it must be borne in 
mind that an essential requisite for the success of this test is a 
perfectly level position of the balance. The equilibrium of the 
beam should also be maintained when the pans are attached, whether 
empty or lightly or heavily loaded, and when the load is transposed 
from one pan to the other ; these tests prove equality in the length 
of the arms. Fine prescription balances should be kept enclosed 
in a suitable case provided with glass sides and top to protect them 
against dust, moisture, and corrosive vapors ; they should not be 
scoured at any time, but simply polished with a piece of soft 
chamois skin or dusted with a soft camel-hair brush ; under no 
circumstances should oil or chalk be used on the knife edges or 
planes. 

Compound lever balances differ from those above described 
chiefly in having the pans situated above the beam and supported 
upon rods so constructed as to retain their vertical position during 
oscillation ; they are less sensitive than the single beam prescription 
balances, and are generally used for coarser weighing. When en- 
closed in a box they are known as " box scales " and then possess 



WEIGHTS AXI) JIEASUBES. 



35 



the advantage of having the more delicate parts of the mechanism 
protected against injury. 

Fig. 4. 




Prescription box scale?. 
Fig. 5. 




Compound lever balance. 



box scales con- 
i) represents a 



Fig. »:. 



Figs. 4 and 5 show prescription and counter 
structed on the compound lever principle. Fig 

convenient dispensing balance for rough 
prescription work, and is intended for 
quantities ranging from 30 grains to '2 
or 4 ounces ; it is sensitive to I grain, 
and is provided with a beam graduated 
iuto apothecaries' and metric weight (1 to 
120 grains and 0.1 to 8.0 (On.) and car- 
rying a sliding poise. 

Special balances for weighing liquids, 
particularly in the laboratory, have been 
found very convenient on account of their 
peculiar construction. Fig. 7 represents Troemner's new solution bal- 
ance, capable of weighing from 10 grammes to 16 kilogrammes (154 
grains to about 36 pounds). The scale is provided with an extra 
balancing beam by which an empty bottle or container is quickly 
balanced by simply sliding the balance weight along until a correct 
balance is secured. A new system of adjusting weights, known as 
the ball system, is attached, and is a great improvement over the old 
method of using separate weights; small weights are adjusted on 




Troemner's dispensing scale. 



36 



GENERAL PHARMACY. 



the graduated beam in front, while the larger weights are repre- 
sented by different positions of the balls on the central plate. 

Since 1882 great improvements have been made in what are 
known as torsion balances. The chief difference between torsion 
and ordinary balances is the entire absence of knife edges and the 
location of the centre of gravity above the fulcrum or point of 

Fig. 7. 




Troenmer's new solution balance. 

rotation. The knife edges have been replaced by thin steel springs 
stretched tightly between bearings, the centre of the beam being 
fastened to the centre of the strained spring and at right angles to 
it ; under this condition the beam, by the elasticity or torsion of the 




Torsion prescription balance. 



H-'-|-H 



I ' |-'-| 



I,'- 1 '''- 1 '! 



3 GRAINS 



I ' I ' I ' I ' 'I I ' I ' I ' I ' I ' I ' I ' I ' ' I ' I ' I ' I ' 'IT 

2 DECIC. 



Section of rider beam for same. 



spring, will vibrate precisely as the ordinary beam balanced on knife 
edges. The pans rest upon similar torsion springs at the ends of 
the beam in the same manner as the central fulcrum of the beam. 
The inherent torsional resistance to oscillation, due to the tightly- 
stretched wire bands, is overcome by elevating the centre of gravity 
above the fulcrum, by means of a weight, to such a height that its 
tendency to reach its lowest position (vertically below the centre of 
rotation) almost neutralizes the total resistance. If, consequently, 



WEIGHTS AND MEASURES. 



37 



the tendency of the high centre of gravity and the resistance of the 
wire bands are opposed to such an extent as to nearly neutralize 
each other, the sensitiyeness of the balance is established, and the 
slightest weight placed on the pans will cause the beams to oscillate ; 
on the other hand, the beams will return to their horizontal position 
by the unneutralized resistance. The foregoing principle has been 
applied to a variety of balances adapted for ordinary commercial 
weighing, as well as the more delicate adjustment of tine prescrip- 
tion work and chemical analysis ; like ordinary balances they are 
provided with graduated beams and poise to be used in place of 
weights. Fig. 8 represents a torsion prescription balance of fine 

Fig. 0. 




Section of triple rider beam foi 



adjustment, with all the parts enclosed in a glass case and fully 
exposed to view ; it is sensitive to 1 milligramme or ^j of a grain, 
and up to 500 milligrammes or 8 grains all weights can be ad- 
justed by. means of a rider on the graduated beam. Fig. 9 repre- 
sents a torsion counter balance sensitive to 2 grains, and having a 
capacity of 20 pounds ; it is also provided with a triple graduated 
beam for avoirdupois, troy, and metric weights. 

Every pharmacist who lays claim to doing even a moderate pre- 
scription business should have in his possession at least two bal- 
ances, one of which may be used for weighing quantities ranging 
from 30 grains to 2 or 3 ounces, and should be sensitive to at least 
J grain; while the other should be confined to quantities never 
greater than 2 grammes or 30 grains, and should respond readily to 
a change in weight amounting to 2 or 3 milligrammes or -^ to ■£$ 
grain ; besides these a larger balance (usually termed counter scales) 
is needed for general trade ; this should be of such adjustment as to 
allow accurate weighing thereon of quantities ranging from J ounce 



38 



GENERAL PHARMACY. 



to 5 or 10 pounds, and should be sensitive to 5 or 10 grains, with a 
full charge. 

Weights are pieces of metal designed to weigh aliquot parts of 
the established units ; brass or iron is used for the customary com- 
mercial weights, while brass or aluminum is chosen for weights 
employed for dispensing purposes ; platinum is also occasionally 
used for small prescription weights on account of its extreme hard- 
ness and resistance to atmospheric influences. Accurate weights 
are as essential as accurate balances, for one is rendered unreliable 
without the other. The usual form of commercial weights at 
present is in sets known as box or block weights and ranging from 
one quarter ounce to five pounds (Fig. 10). Troy weights as a 

mark of distinction from avoirdupois 
weights are usually sold in nests of 
brass cups (see Fig. 11); they run 
from one-eighth ounce to eight or 
sixteen ounces, and for use in dispens- 
ing prescriptions the lower denomi- 
nations, from J grain up to 2 ounces, 
are frequently put up in boxes or 
blocks as shown in Fig. 12. The 
smaller dispensing weights are either made of brass or nickel- 
silver, after the style shown in Fig. 13, or of aluminum if below the 



Fig. 10. 




Block "weights. 



Fig. 11. 



w W$ 




I 

Set of apothecaries' cup weights. 



Fig. 13. 



Fig. 12. 




Apothecaries' weights {% gr 
to Sij) in case. 



Brass or silver-nickel prescription Aveights. 



denomination of ten grains (see Figs. 14 and 15) ; weights 
less than one-quarter grain are often indicated by means of a 
sliding poise on a graduated beam. The relative lightness of 
aluminum adapts this metal admirably for use in weights of very 



V EIGHTS AND MEASURES. 



39 



low denominations, as they can be made of larger size and con- 
sequently be more conveniently handled than heavier brass weights. 
Metric weights are made of iron, brass, or aluminum, in the same 
forms as already described for avoirdupois and apothecaries' weight. 



Fig. 14. 



Fig. 15. 




Aluminum -wire weights. 



Aluminum grain weights. 



In connection with the operation of weighing, the term tare is 
frequently used to indicate the weight of the empty vessel (dish, 
box, bottle, or jar), in which the substance (liquid or dry) is to 
be weighed ; gross weight is the combined weight of the substance 
and the container, net weight is the weight of the substance alone, 



Fig. ic. 




Set of metric prescription weights. (100 grammes to 1 centigramme. 



obtained by subtracting, from the gross weight, the tare of the con- 
tainer. Instead of finding the exact weight of the container, the 
latter may be simply counterpoized or balanced by small shot or dry 
coarse sand contained in a suitable cup. 

Everyone who has occasion to use line balances should early 
accustom himself to certain habits of care and neatness, which will 
materially preserve the sensitiveness of the instrument. The fol- 
lowing rules are recommended: Neve)- allow the beam to oscillate 
when the balance is not in use. Immediately after the operation of 
weighing is completed, replace the weights in their proper receptacle and 
clean the pans with a soft towel. Never weigh deliquescent salts, or 
active chemicals, such as iodine, on the metal pans, but always on glass, 



40 



GENERAL PHARMACY. 



or in tared vessels. Ahvays weigh potent or poisonous drugs on stiff- 
glazed paper, using two pieces of equal size to counterpoise each other. 
Never place large weights on the pans, or remove them, while the beam is 
in motion ; this is easily accomplished by means of levers for keeping the 
beam and pans at rest. 

Measures are vessels used for determining the volume of liquids, 
and even dry substances ; the latter kind do not concern the phar- 
macist, who is compelled, however, to have on hand a variety of 
vessels suitably provided with appropriate scales of measurement for 
liquids. Such vessels are usually made of glass and are known simply 
as graduates ; they occur of different capacities from 1000 cubic centi- 
meters (1 liter) down to 5 cubic centimeters, and from 64 fluid- 
ounces down to 60 minims. The Phenix and Acme Graduates, 
manufactured in this country, are guaranteed to be accurate and 
made strictly according to the American standard of apothecaries' 
fluid measures ; since Imperial measure differs materially from U. S. 
fluid measure, graduates made in England cannot be used in this 
country, unless they have been adjusted according to the American 
standard. Very accurate metric graduates are also now made in 
this country. 

Graduates of different shapes are in use, conical, tumbler- 
shape, and cylindrical (see Figs 17, 18, 19), the last named of winch, 



Fig. 17. 



Fig. 18. 



Fig. 19. 






illll^-SIII 

■"fill! 

■h.'IIii iiiiiin llllli"'":. 

III. 

' Ill 

in 




Conical graduate. 



Tumbler-shape graduate. 



Cylindrical graduate. 



although the most accurate, are but rarely seen in stores. Cylindri- 
cal graduates have a small diameter, which is uniform throughout 
the height of the vessel ; hence errors in measurement due to capil- 
lary attraction are in these reduced to a minimum. For J and \ oz. 
graduates the diameter is about \ inch ; for 1 and 2 oz. sizes it 
should not exceed f inches; while for the 4 oz. size, \\ inch diameter 



WEIGHTS AXB MEASURES. 



41 



will be ample. For measuring quantities less than two flnidounees 
the cone-shaped graduates will be found preferable to the tumbler- 
shape, but difficulty is often encountered in cleaning them properly, 
particularly the smaller sizes. The " Acme" graduates, introduced 
a few years ago, possess the advantage of being made flat on the 
bottom, without a foot, and hence are less liable to be upset or 
broken ; they arc admirably adapted for laboratory work, are cylin- 
drical in form, of about the same diameter as tumbler-shape gradu- 
ates, and can be had for both metric and apothecaries' fluid measure. 
(See Figs. 20 and 21.) 



Fig. 20. 



Fig. 21. 




Metric fluid measure. 




fluid measure. 



Acme graduates. 



Duplex graduates, arranged for apothecaries' fluid measure on one 
side and metric fluid measure on the other, are not to be recommended, 
on account of the danger of confusion and the greater difficulty of 
accurate measurement. 

Although minim graduates are extensively employed for measur- 
ing volumes of less titan one-fourth fluidounee, it will be found more 
desirable to use minim pipettes (see Fig. 22) for quantities ranging 
from 5 to 60 minims; these instruments, flrst suggested by Dr. E. 
E. Squibb, are very accurately made and will be found extremely 
convenient. For measuring small metric volumes the graduated 
cubic centimeter pipettes of Dr. Curtman will be found very 
serviceable (see Fig. 23) ; they come in different sizes — 5 and 10 and 
25 Ce. capacity — each cubic centimeter being divided into tenths, and 
are especially adapted to pharmacopceial testing. 

As to the proper manner of holding a graduate while measuring 
liquids, it may be said that the firmest hold is obtained by grasping 
the graduate with the left hand in such a manner that the first or 
index finger encircles the lower part of the vessel, the thumb resting 
on the base and the second finger forming a support by being placed 
under the base ; this leaves the third and fourth fingers free to remove 



42 



GENERAL PHARMACY. 



and hold the stopper of a bottle from which any liquid is to be meas- 
ured ; the mark to which the liquid is to be measured should be on a 
level with the operator's eye while the graduate is held in an upright 
position. Owing to capillary attraction, every liquid contained in a 



Fig. 22. 




w 



KJ 



w 

Dr. Squibb's minim pipettes. 



Fig. 23. 



torn 

9.51 
9.o\ 
8.5 
8.0 1 

7.51 

w\ 

6.51 

6j0\ 

5.b\ 

5.0 

45 

4.0 

3 A 

3.01 

2 A 

2.0\ 

1.5 

1.0 \ 

0.5 
0^ 



Dr. Curtman's cubic centimeter pipette. 



graduate will present two concave surfaces, neither of which can be 
taken as the true level ; hence a correct reading of the graduation 
can only be had by fixing the desired marking of the scale inter- 
mediate between the upper and lower edges of the liquid. 

Graduates which have the same scale marked on both sides, or 
which are encircled by the markings of the scale, admit of more 



WEIGHTS AXD MEASURES. 



43 



accurate measurements and do not require that careful attention to 
levelling the graduate necessary with the plainer varieties. 

Glass graduates are best cleaned by washing with a mop, using 
soap and water if necessary, rinsing with clear water and allowing 
the graduate to drain, either on a perforated tray or by hanging in 
a rack, but never should a towel be used to dry the graduate, as it is 
apt to leave lint adhering to the glass. 

Approximate Measurements. Owing to the varied density 
of liquids, the number of drops contained in a certain volume must 
vary greatly with different liquids ; moreover the size of a drop is 
influenced by the size and shape of the vessel from which the drop 
is allowed to fall — so that a drop is a very uncertain quantity in the 
division of doses of medicines. The variability of adhesion to 
glass exhibited by different liquids as well as the rapidity with 
which liquids are allowed to flow from vessels, are other factors 
which determine the size of drops, as is shown in the case of chlo- 
roform. 

Instead of being identical with the minim, drops may vary from 
one-fifth to one and one-fourth minim. 

For the purpose of better illustration, the following short table has 
been inserted, showiug the great variability in size of drops of 
different liquids : 



Table Showing the Nl 


mber of Drops to a 


Fluidracitm:. 




120 minims 


1 fluidounce 


W. T. & Co's. 




Liquid. 


Phenix 


l'lu'iiix 


exact Medi- 


Pint or Quart 




Graduate. 


Graduate. 


cine Dropper. 


Shelf Bottle. 


Distilled Water .... 


48 


46 


128 




Tincture of Aconite . 


150 


150 


190 


120 


" " Belladonna 


144 


144 


174 


108 


" Chloride of Iron 


150 


150 


190 


120 


" Opium . 


130 


130 


154 




" Camphorated 


13(5 


136 


170 




" " Deodorized Opium . 


90 


110 


124 


80 


Glycerin ... 


90 


76 


90 




Purified Chloroform . 


234 


240 


304 


160 


" " second trial 


274 


279 


360 


180 


Dil. Hydrocyanic Acid 


60 


80 


75 


60 










(3J bottle) 



ig capacity 



For the administration of medicines certain familiar domestic 
measures are employed, which, although subject to considerable vari- 
ations, are usually estimated as having the following 

A teaspoonful, equal to one fluidrachm ; 

A dessertspoonful, equal to two fluidrachms ; 

A tablespoonful, equal to one-half fluidounce ; 

A wineglassful, equal to two fluidounces ; 

A teacupful, equal to four fluidounces ; and 

A tumblerful, equal to eight fluidounces. 



44 



GENERAL PHARMACY. 



Figs. 24, 25, and 26 represent convenient medicine glasses, well 
adapted for family use. 



Fig 24. 




Fig. 25. 




Fig. 26. 



0k ,., 




Graduated medicine glasses. 



These vessels are now obtainable, accurately graduated and made 
to correspond to apothecaries' fluid measure — hence they are prefer- 
able to the variable tea-, dessert- and tablespoons generally met 
with, and should be employed altogether in the sick-room. 



CHAPTER III. 

SPECIFIC GRAVITY. 

A knowledge of the subject of specific gravity is of importance 
to the pharmacist, as it frequently enables him to detect impurities or 
to determiue the identity and quality of the drugs he handles. Spe- 
cific gravity means relative weight, or the relation between the 
volume and weight of bodies as compared with a standard — the 
standard for liquids and solids being distilled water, while atmos- 
pheric air or hydrogen is used for gaseous bodies; in other words, 
specific gravity is the ratio between the weight of any gaseous, liquid, 
or solid body and that of an equal volume of the respective standard. 

The principle of specific gravity was first announced by Archi- 
medes, a Greek philosopher, who formulated the law that all bodies 
immersed in a liquid are buoyed up with a force equal to the weight 
of the liquid displaced by them; hence a piece of metal of the size of 
one cubic inch, when immersed in water, will exert as much less 
pressure on the bottom of the container as will equal the weight of 
one cubic inch of water — or a fraction over 252 grains. Floating 
bodies always displace their own weight of water, irrespective of their 
volume, while immersed bodies always displace their own volume of 
water, irrespective of their weight; hence all bodies whose volume 
weighs less than an equal volume of water are sure to float, only so 
much of the body being immersed as equals a like weight of water, 
while all bodies whose volume weighs more than an equal volume of 
water must sink and be completely immersed, as this downward 
pressure of the body exceeds the upward pressure or buoyant force 
of an equal volume of water. 

As the volume of all bodies varies with temperature, it is essential 
that the comparison of weights be made at some fixed temperature 
and that equal volumes of the standard and body examined be 
weighed at the same temperature. In some countries the tempera- 
ture of 4° C. (39.2° F.), at which pure water assumes its greatest 
density, is taken for the comparison of weights, while in the 
United States and German Pharmacopoeias, 15° C. (59° F.) has been 
fixed, with very few exceptions, as the normal temperature; the 
British Pharmacopoeia has selected 15.6° C. (60° F.). As the com- 
parison of weight of equal volumes of bodies may be made at any 
temperature desired or convenient, and as the specific gravity will 
vary accordingly, it is necessary to state the temperature in connec- 
tion with specific gravity; for instance, to say that a liquid lias the 



46 GENERAL PHARMACY. 

specific gravity 1.42, would not indicate at what temperature the 
liquid had been weighed, nor would it indicate comparison with 
water at the same temperature — hence the ratio would be an un- 
certain expression; to say that a liquid has the specific gravity 1.42 
at 15° C, would still leave a doubt as to the temperature at which 
an equal volume of pure water had been weighed for comparison, for 
it may have been 4° C, 12° C, or even 25° C, and, in either case, 
the specific gravity named would not be absolutely correct; to say, 
however, that a liquid has the specific gravity 1.42 at 15° C. as 
compared with water at the same temperature, leaves no room for 
doubt as to the true ratio existing between the liquid and water — it 
therefore expresses the true specific gravity. The United States 
Pharmacopoeia (1890) expressly states that all of its specific gravities 
are to be considered as taken at 15° C and compared icith ivater at the 
same temperature, whenever no special temperature is mentioned. 

As it is frequently more convenient to weigh substances at a tempera- 
ture above 15° C. than to cool the substance down and keep it at 
that point, the average room-temperature, 22° C. (71.6° F.), or even 
25° C. (77° F.), has been suggested by some authorities, and will 
often be found preferable. 

Barometric pressure is not without effect on the relation between 
the volume and weight of bodies, hence absolute specific gravity, like 
absolute weight, is only obtainable in vacuo ; for pharmaceutical pur- 
poses this difference is always ignored and the barometric pressure 
assumed to be normal, 760 Mm. or 30 inches. 

The specific gravity of a solid or liquid is always expressed by a 
number which shows how often the weight of a certain volume of 
water is contained in the weight of the same volume of that solid or 
liquid ; and the specific gravity of a gaseous body is expressed by a 
number which shows how often the weight of a certain volume of 
atmospheric air (or hydrogen) is contained in the weight of the same 
volume of that gaseous body. The specific gravity of water is 
therefore stated to be 1, aud the specific gravity of air (or hydrogen) 
is likewise stated to be 1. The following simple rule may be given 
for finding the specific gravity of any liquid or solid substance by 
calculation : Divide the weight of a given volume of any liquid or 
solid by the weight of an equal volume of distilled water, both 
weighings having been made at the same temperature. The quotient 
expresses the specific gravity. 

Specific Gravity of Liquids. 

The determination of the specific gravity of liquids is far more 
frequently required than that of solids. The different instruments 
employed for that purpose are specific gravity flasks or pycnometers, 
loaded glass cylinders, specific gravity beads, and specific gravity 
spindles or hydrometers. Any small flask, of 25 or 50 Cc. capacity, 
with a long, narrow neck and made of thin glass, will answer as a 



SPECIFIC GRAVITY 



47 



specific gravity bottle. Its weight, or tare, is first carefully ascertained 
and noted ; pure water is then poured into the flask until it reaches a 
short distance up into the neck, when a mark should be made with a 
file at the upper and lower edge of the meniscus or concave surface ; 
having noted the temperature of the water, the flask and contents 
are weighed, and from it the tare of the flask is deducted, the re- 
mainder being the weight of that particular volume of pure water at 
the given temperature. The tare, temperature and weight of water, 
are carefully etched on the side of the flask, which is now ready to 
be used for taking the specific gravity of any liquid, by filling it to 
the mark in the neck with the liquid to be tested, then weighing and 
dividing the net weight of the liquid by the weight of the water, 
the quotient being the specific gravity of the liquid. Suppose the 
flask weighs 324 grains and holds, up to the mark, 647 grains of 
water ; filled to the mark with sulphuric acid, it weighs 1511.5 grains, 
which leaves 1511.5 — 324 = 1187.5 grains as the weight of the 
acid. Xow applying the rule, to divide the weight of a given 
volume of a liquid by the weight of the same volume of water, the 
specific gravity is found to be 1187.5 h- 647 = 1.835-f-. 

Fig. 27. 





6 



Glass-stoppered specific gravity bottle with tin case and counterpoise. 



Small glass-stoppered flasks, graduated to hold 100, 250, 500, or 
1000 grains of distilled water at 15.6° C. (60° F.), are a more con- 
venient form of pycnometer ; they come packed in tin cases and are 
accompanied by a metal counterpoise to balance the empty bottle 
(see Fig. 27). In using these flasks it is necessary to fill them with 
the liquid to be tested, to a little above the mark in the neck to 
which the glass stopper reaches when inserted, so that the air and 
small excess of liquid shall be forced out through the capillary tube 



48 



GENERAL PHARMACY. 



drilled through the stopper. The liquid to be tested, having the 
same temperature as that at which the flask has been adjusted, may 
be weighed, after wiping the flask dry, when, in the case of the 100 
or 1000-grain bottle, the weight at once expresses the specific gravity, 
by simply placing the decimal point correctly, without further cal- 
culation ; for, as the weight of water (100 or 1000 grains) is to the 
weight of the same volume of any liquid, so is the specific gravity of 
water (1.000) to the specific gravity of that liquid. Example : If the 
100-grain bottle be found to hold 141.5 grains of a certain acid, the 
specific gravity of that acid will be 1.415 ; for 100 : 141.5 : : 1.000 : 
x. x = 1.415. 

For the general purposes of the pharmacist, the above-described 
specific gravity bottles give results sufficiently accurate, the most 
annoying practical difficulty lying in the proper adjustment of the 
temperature. At certain seasons of the year the prescribed tempera- 
ture of 15° or 15.6° C. is readily attained; but in summer, when the 
temperature of the atmosphere frequently reaches 32° C. (89.6° F.) 
and over, the dew-point rises above 15.6° C. and moisture is deposited 
on the outside of the cooler bottle while weighing, thus sensibly in- 
creasing its weight. The following table, taken from Parrish's Treatise 
on Pharmacy, was compiled by Dr. W. H. Pile, and is based on the 
corrections made for contraction and expansion of the 1000-grain 
bottle used, as well as the water : 

Table of Apparent and True Specific Gravity of Water as Observed 
in a Glass Bottle at Different Temperatures. 



Temp. Fahr. 


Sp. Gr. in 
Glass Bottles. 


True Sp. Gr. 


Temp. Fahr. 


Sp. Gr. in 
Glass Bottles. 


True Sp Gr. 


50° . 


1000.54 


1000.67 


72° . 


998.94 


998.78 


51 






1000.50 


1000.62 


73 


998.83 


998 66 


52 






1000.46 


1000.56 


74 . . 


998.72 


998 53 


53 






1000.41 


1000.50 


75 . . 


998.60 


998.40 


54 






1000.36 


1000.44 


76 . 


998.48 


998.27 


55 






1000.30 


1000.37 


77 


998 35 


998.13 


56 






1000.25 


1000.30 


78 


998.22 


997.99 


57 






1000.20 


1000.23 


79 


998.08 


997.84 


58 






1000.14 


1000.16 ! 


80 


997.94 


997.68 


59 






1000 07 


1000.08 


81 


997.79 


997.52 


60 






1000.00 


1000.00 


82 


997.64 


997.36 


61 






999.92 


999.91 


83 


997.49 


997.20 


62 






999.84 


999.82 


84 


997.35 


997.04 


63 






999.72 


999.72 


85 


997.20 


996.87 


64 






999.68 


999.63 


86 


996.94 


996.60 


65 






999.60 


999.53 


87 


996.78 


996.43 


66 






999.51 


999.43 


88 


996.62 


996.26 


67 






999.42 


999.33 


89 


996.46 


996.08 


68 






999.33 


999.23 


90 


996.29 


995.90 


69 






999.24 


999.12 


91 


996.12 


995.72 


70 






999.14 


999.01 


92 


995.96 


995.54 


71 






999.04 


998.90 


93 

1 


995.79 


995.36 



SPECIFIC GRA VITY 



49 



With a view of overcoming the difficulties usually encountered and 
of insuring more accurate results, Dr. E. R. Squibb has had con- 
structed a set of specific gravity bottles which are equally well adapted 
to all standards of temperature from 4° C. to 25° C. (39.2° F. to 
77° F.) (See Fig. 28.) By means of the long narrow tube stopper, 
graduated into half-millimeters, the volume of liquid in the bottle is 
capable of very accurate adjustment. When first adjusted, the zero 
mark on the scale indicates the point to which the volume of the 



Fig. 28. 





standard weight of recently boiled distilled water reaches at 4° C, 
while the upper limit of the scale indicates the volume at 25° C. 
Since glass bottles contract appreciably for two years or more after 
they have been made, the graduations should be verified every six 
months or more until contraction has ceased, a memorandum of 
the changes being kept for reference when the bottle is to be 
used ; thus the point for the volume at 4° C. may have advanced 
from to 2 or 3 divisions of the scale, and similarly for any tempera- 
ture volume. The bottles are always used in a bath of either warmed 

4 



50 



GENERAL PHARMACY. 



Fig. 29. 




Fig. 30. 



or cooled water, and when the volume does not change for five 
minutes, as indicated by the graduated scale, the contents of the 
bottle may be known to have assumed the temperature of the bath 
as ascertained by means of a delicate thermometer. A leaden col- 
lar is used to keep the bottles steady in the bath, and the adjust- 
ment of volume is made by means of a fine pipette and blotting 
paper. 

Besides taking the specific gravity of liquids by means of a 
pycnometer, accurate results may be obtained with the so-called loaded 
cylinder ; its use is far less troublesome, and as it can be 
employed at any temperature between 4° and 40° C. (39.2° 
and 104° F.) it requires less careful attention to the ad- 
justment of the latter. The loaded cylinder, as shown in 
Fig. 29, consists of a glass tube partly filled with mercury 
and sealed at the top, to which is affixed a hook for con- 
venient suspension to a scale beam. Having 
weighed the cylinder in air and then in pure 
water, at any given temperature, the weight of 
an equal volume of water is ascertained by 
subtracting the weight in water from the 
weight in air ; the cylinder is then weighed 
in any desired liquid at the same temperature 
as the water, and the loss in weight again 
noted, which is the weight of an equal volume 
of that liquid. The volume of the liquid 
to be tested, being equal to the volume of the 
cylinder, must be equal to the volume of water 
also, for things that are equal to the same 
thing are equal to each other ; by dividing the 
^Hnder ^veight of the given volume of the liquid by 
the weight of the same volume of water, the 
specific gravity of the liquid is obtained. Example : A loaded 
cylinder weighs in air 150 grains, and in water 120 grains, loss of 
weight in water 30 grains ; weighed in sulphuric acid it weighs 
96 grains, showing a loss of 54 grains ; equal volumes of the acid 
and water weighing 54 and 30 grains respectively, the specific gravity 
of the acid must be 1.800, for 54 -~ 30 = 1.8. 

When only a small quantity of liquid is available for taking the 
specific gravity the loaded cylinder may be replaced by a small glass 
or platinum weight of the shape shown in Fig. 30; or Grauer's 
method may be followed. This consists in using a small pipette 
having a fine orifice at one end, and at the upper end a short piece 
of rubber tubing closed by a pinchcock ; a mark is made on the 
glass stem, showing the height to which a convenient quantity of 
water rises (say 1.0 Gm. or 1.0 Cc), and enough of the liquid to be 
tested is drawn up through the tube to the mark previously made, 
the tube is closed, and the whole then weighed ; the weight of the 
liquid in grammes expresses the specific gravity with sufficient accu- 





Glass or metal 
plummet. 



SPECIFIC GBA YITY 



51 



racv for all practical purposes, as water increases its volume from 4° 
to 100° C. only to the extent of 0.012, or about ^. 

The principle of the loaded cylinder has been utilized in the con- 
struction of the Mohr specific gravity balance, of which the West- 
phal modification is a most desirable improvement (see Fig. 31). 
The specific gravity of a liquid can be quickly taken at any temper- 
ature between 7° and 30° C, since the loaded cylinder has been 
replaced by a short glass thermometer, which is suspended from the 



Fig. 31. 




The Westphal specific gravity balance. 



end of the beam by a thin platinum wire; the adjustment having 
been made at 15 C., a slight variation will be observed for any 
higher or lower temperature. The small thermometer has a range 
of twenty-three degrees on the Centigrade scale, and, when suspended 
in air from the longer arm of the beam, establishes perfect equilib- 
rium; when completely immersed in distilled water at 15° C. it 
displaces its own volume of the water aud is buoyed up by a force 
equal to the weight of the water displaced — equilibrium of the beam 
being re-established by attaching the necessary counterpoise, which 



52 GENERAL PHARMACY. 

is called 1.000 : at 7.5° C. the necessary weight was found to 
be 1.001, while at 27° C. it was 0.998. As seen in the illustration, 
the longer arm of the beam is accurately divided into ten even spaces, 
and the weights, or riders, used to counterbalance the thermometer 
when immersed in any liquid, are made of brass and aluminum j 
they are so constructed that each smaller rider is of exactly -^ the 
value of the next larger, the largest rider and the counterpoise 
used to balance the thermometer in water, however, being of the 
same weight or value. Without the necessity for calculation, if 
the temperature of the liquid be at 15° C, the specific gravity of the 
liquid can be at once read off, after the equilibrium of the beam has 
been established ; for iustance, in testing alcohol at 15° C, the 
counterpoise necessary to balance the beam in water will be found 
too heavy if attached at the same point in alcohol, hence it is 
removed, and the largest rider is placed in the first, or, if necessary, 
in the second notch on the beam, where it may appear a little too 
light, and then the smaller riders are added as may be necessary 
to balance the beam perfectly. The value of each of the two larger 
riders, when suspended from the end of the beam, is considered as 
1.000, while the three smaller riders are valued at 0.100, 0.010, and 
0.001 respectively ; when removed to the top of the beam the value 
of each rider is reduced by y 1 ^- for every notch. If one of the large 
riders be placed at the notch marked 8, a second rider at 2, and a 
smaller rider at 1, the specific gravity of the alcohol must be read 
as 0.821. In the case of chloroform and all other liquids specifically 
heavier than water the large counterpoise is suspended from the end 
of the beam, and the other riders are placed in the notches as may 
be necessary; thus chloroform may require all four riders on the 
beam, the largest at 4, the second at 8, and the smaller two at 9, 
which would be read as 1.489 specific gravity. Whenever two 
riders of different weight are required in the same notch on the 
beam, the lighter of the two is suspended from the hook of the 
heavier, as shown in Fig. 32; thus the specific gravity of liquids 
can be read with accuracy to four decimal places. The Mohr or 
Westphal balance cannot be used, however, if only very small 
quantities of liquid are available, as sufficient liquid is required to 
immerse the glass thermometer completely. 

Specific gravity beads, also known as Lovi's beads, are small, 
sealed, pear-shaped glass bulbs of various specific weights, which 
have been carefully ascertained and are marked on them; these 
beads will float indifferently in any liquid having the same specific 
gravity, and may be used in reducing liquids to a fixed specific 
gravity by dilution or evaporation. If a bead marked 0.93 be 
placed in ajar of alcohol it will sink — unless the liquid happens to 
be official diluted alcohol — but will slowly rise upon the addition 
of water, until a sufficient quantity has been added to increase 
the specific gravity of the mixture to that indicated on the bead, 
when it will float about midway in the liquid. Eesults obtained 



SPECIFIC GRAVITY. 



53 



with specific gravity beads are never so accurate as with other 
methods. 

Hydrometers, or areometers, are instruments intended to indicate 
either the density or specific gravity of liquids, and in some cases 
also the perceutage by volume or weight of certain liquids. They 



Fig. 32. 




13683 



1.7427 



.5522 



.0460 



0.8642 



Showing the manner of reading the specific gravities. 



consist of a glass tube having a bulb blown at one end, a little 
above which the tube is usually expanded cylindrically for a short 
distance, and then terminates in a long stem in which is securely fast- 
ened a graduated paper scale (see Fig. 33). The bulb is filled with 
mercury or small shot, so as to enable the instrument to assume a 
vertical position when floated in any liquid. Hydrometers, like all 
floating bodies, displace their own weight of a liquid and sink in it 
to a depth proportional to the volume of liquid displaced, which 
volume is equal in weight to the weight of the instrument ; thus, by 



54 



GENERAL PHARMACY. 



Fig 33. 



comparison of volumes displaced, the densities and specific gravities 
of various liquids can be ascertained. While the great majority of 
hydrometers are so constructed that with constant weight 
they will sink to varying depths in different liquids, some 
are made to sink to a uniform depth in all liquids by 
the addition or subtraction of weights, and the density, 
or specific gravity, is calculated from such change of weight ; 
this latter class can also be conveniently used for taking 
the specific gravity of solids. 

Specific gravity hydrometers are made with the unit 
mark 1.000 at a point to which the instrument sinks in 
distilled water at normal temperature (usually 15.6° C. or 
60° F.), and then have the scale carried above and below 
this point, each mark on the scale indicating either 0.001, 
or 0.005, or 0.010, according to the intended delicacy of 
the instrument. As specific gravities of liquids range 
from 0.700 to above 2.00, the tube of a hydrometer carry- 
ing such a scale would have to be inconveniently long to 
permit of a fair reading of it ; hence specific gravity 
hydrometers usually come in sets of four, ranging from 
0.600 to 1.000, from 1.000 to 1.400, from 1.400 to 
1.800, and from 1.800 to 2.200. When intended for test- 
ing the specific gravity of special liquids the scale is usually 
much shorter, and thus permits of more accurate gradu- 
ation. 

By far the larger number of hydrometers are intended 
for determining the density of liquids irrespective of spe- 
cific gravity ; they are extensively employed for technical 
purposes and are based on arbitrary scales, no two of 
which agree, but which can be converted into specific 
gravity by certain rules. To this class belong Baume's, 
Twaddell's, Carrier's, Zanetti's, Sikes', Beck's, Jones' 
and other hydrometers. Since Baume's hydrometers are 
largely used by manufacturing chemists in this country, 
and the degrees Baume are often stated on labels, the 
instrument is of special interest to pharmacists. 

Baume had two hydrometers, one for liquids heavier 

than water and the other for liquids lighter than water; 

the former was called Pese-Acide, or Pese-Sirop, and the 

latter Pese-Esprit. For liquids heavier than water the 

zero was placed at the point to which the instrument 

distilled water at 15.6° C, and the point to which it 

a solution of 15 parts of dry table salt and 85 parts of 

water, also at 15.6° C, was marked 15; the distance 

these two points was then divided into 15 equal parts, 




Hydrome- 
ter plain. 



sank in 
sank in 
distilled 



between 

called degrees, and the scale extended as far as the length of the tube 
would permit. The zero for liquids lighter than water was found 
by immersing the instrument in a solution of 10 parts of dry table 



SPECIFIC GRAVITY. 



55 



Fig. 34. 



10 



20 



30 



40 -=- 



50' "r- 



60 -=- 



FlG. 35. 
Q 
70 

60 

50 



salt and ninety parts of distilled water at 15.6° C. in such a way 
that the long stem would be almost entirely out of the liquid ; the 
point to which the instrument sank in distilled water, also at 15.6° 
C, was marked at 10, the space between the two points being divided 
into 10 equal parts and the scale extended as in the other case. The 
slightest error in obtaining the first interval is increased upon ex- 
tension of the scale; hence it is almost impossible to find two instru- 
ments adjusted by the old method to correspond exactly. A more 
accurate and equally practicable method is to obtain the exact 
specific gravity of two liquids compared with distilled water at a 
fixed temperature, place these at the extremes of the scale, and then 
divide the intervening space into the requisite number of degrees. 
The liquids chosen in this country, for liquids heavier than water, 
are concentrated sulphuric acid having the specific gravity 1.8354 
at 15.6° C, and distilled water; and for liquids lighter than water, 
highly rectified ether having the specific gravity 0.725 at 15.6° C, and 
distilled water; the space between the 
points to which the hydrometer sinks 
in the water and the acid is divided into 
66 parts, or degrees, and the space be- 
tween the points to which it sinks in 
the ether and the water into 53 parts. 
For all liquids heavier than water the 
scale is read from above downward, 
while for liquids lighter than water 
it is read from below upward. (See 
Figs. 34 and 3-").) 

As it is frequently desirable to know 
the specific gravity for any given de- 
gree on the Bau me scale, and vice versa, 
the following rules have been formu- 
lated. 

For liquids heavier than water: 
Subtract the degree Bau me from 145 
and divide the remainder into 145 to 
find the specific gravity. 

Divide 145 by the specific gravity 
and subtract the quotient from 145 to 
find the degree Baume. 

For liquids lighter than water: Add 
the degree Baume to 130 and divide 
the sum into 140 to find the specific 
gravity. 

Divide 140 by the specific gravity 
and from the quotient subtract 130 to 
find the degree Baume. 

The moduli or constants employed in these rules express the pro- 
portion which the weight of water displaced by the hydrometer when 



40 



30 



40 



10 




4 



Baume's Hydrometers. a, for 
liquids heavier than water ; b, for 
liquids lighter than water. 



56 



GENERAL PHARMACY. 



Fig. 



floating in water bears to the weight of water equal in bulk to one 
degree. Thus, if a Baume hydrometer be floated in water at on 
the hydrometer for heavier liquids, or at 10 on the hydrometer for 
lighter liquids, it will require the addition of j\^ of the weight of 
the hydrometer to sink it one degree in the first case, or the with- 
drawal of y^q- of its weight to allow it to rise oue degree in the 
second case. The fact that the water-line is marked at 10 instead 
of 0, on Baume hydrometers for liquids lighter than water, necessi- 
tates the use of 130 instead of 140 in the foregoing rule. 

In order to avoid the use of rules and tables in connection with 
arbitrary scales, hydrometers have been in use for some years bear- 
ing a double scale, for Baume degrees and the 
corresponding specific gravity, as shown in Fig. 36 : 
they come in sets, usually five, two of which are 
intended for liquids lighter than water, and three 
for liquids heavier than water, the shorter size 
permitting closer reading within smaller limits. 

The Twaddell hydrometer is only for liquids 
heavier than water, each degree on the scale being 
equal to 0.005 specific gravity ; hence the requisite 
number of degrees multiplied by 0.005 and added 
to 1.000 expresses the specific gravity of any 
liquid ; thus, if a sample of glycerin stands at 50° 
Twaddell, its specific gravity will be 1.250, for 
50 X 0.005 = 0.25 and 1.0 + 0.25 == 1.25. 

Nicholson's and Fahrenheit's hydrometers are 
of the kind intended to sink to a uniform depth 
(indicated by a mark on the stem) in all liquids, by 



Double hydrometer for 
density and specific grav- 
ity determinations. 




Nicholson's hydrometer. 



the use of weights. Fig. 37 represents a Nicholson hydrometer 
floating in a liquid. The construction is readily explained : A is an 
elongated glass or metal bulb, terminating in a stem surmounted by 
a metallic disk, b ; on the stem is a mark at D, indicating the point 



SPECIFIC GRAVITY. 



57 



Fig. 38. 



I 



to which the instrument must be made to sink, and attached to the 
bottom of the bulb by means of a small hook is a loaded cup, c, for 
carrying solids if so desired. When the hydro- 
meter is immersed in water, sufficient weights are 
placed ou the disk, B, to cause the instrument to 
sink to the point D ; it is then transferred to the 
liquid to be tested, and the weights adjusted as 
before ; the weight necessary to sink the hydro- 
meter to the proper point represents the weight of 
the volume of liquid displaced by it ; hence the 
weight necessary in the case of any liquid, divided 
by the weight required in the case of water, gives 
the specific gravity of that liquid. 

Spirit hydrometers, usually called alcoholom- 
eters, are used to ascertain the percentage of 
absolute alcohol in the commercial article ; since 
the value of alcohol depends entirely upon the 
amount of absolute alcohol present, this instru- 
ment is a most desirable piece of apparatus for 
pharmacists. Alcoholometers are made of glass, 
like ordinary hydrometers, but of much longer 
shape, and are usually provided with tw r o separate 
scales — Richter's scale, indicating the percentage of 
alcohol by weight, and Tralles' scale, showing the 
percentage by volume; since the instrument is ad- 
justed at 15.6° C. (60° F.) it becomes necessary to 
make proper corrections for any variations in temper- 
ature. When immersed in alcohol at normal tem- 
perature the figures on the respective scales to which 
the instrument sinks indicate the number of parts 
of absolute alcohol contained in 100 parts of the 
specimen, the lowest mark on the scale being 0, to 
which the hydrometer will sink in pure water. 
Since a cold temperature, by contraction, increases 
the density of alcohol the instrument cannot sink 
so low in the liquid if the temperature be below 7 
15.6° C. as when normal ; an additive correction 
in the reading of the scale must therefore be made. 
On the other hand, if the temperature rise above 
15.6° C. the density of the alcohol will decrease and 
the hydrometer will siuk lower, hence a subtractive 
correction must be made for temperature. The 
necessary correction has been ascertained to amount 
to 0.27 of 1 per cent, for every degree on the Centi- 
grade scale, or 0.15 of 1 per cent, for every degree 
on the Fahrenheit scale. For example, if an 
alcoholometer sinks in alcohol to 93° on the Tralles' Alcoholometer with 
scale at 50° F. (10° C), the liquid contains really thermometer enclosed 



58 



GENERAL PHARMACY. 



94.5 per cent, of absolute alcohol by volume, iustead of 93 as indi- 
cated on the scale, for the temperature is 10° Fahrenheit below the 
normal, hence 10 X 0.15, or 1.5, must be added ; but if the tempera- 
ture had been 70° F. (21.11° C.) the true percentage of alcohol by 
volume would have been only 91.5, for, the temperature being 10° 
above normal, a subtraction of 1.5 from the reading 93 is necessary. 
Fig. 38 represents a complete alcoholometer carrying a thermo- 
meter within the tube for convenience in taking the temperature of 
the liquid. For testing the specific gravity of urine a small hydro- 
meter the range of which extends from 1.000 to 1.060 is employed 
(see Fig. 39) ; the narrow cylinder in which to float the urinometer 



Fig. 40. 



i. 



Fig. 39. 




Fig. 41. 





Dr. Squibb' s urinome- 
ter and cylinder. 



Eichborn's areo- 
pycnometer. 



Rousseau's densimeter. 



was specially designed by Dr. Squibb with the view of preventing the 
hydrometer from adhering to its sides, by means of the peculiar 
indentations. 

Special instruments have been devised for taking the specific gravity 
of very small quantities of liquids; namely, Eichhorn's areo-pyc- 
nometer (Fig. 40) and Rousseau's densimeter (Fig. 41) : instead of 



SPECIFIC GRAVITY. 59 

floatiog these instruments in the liquid to be tested, the latter is carried 
in the hydrometer, which is then floated in water. The illustration 
of the areo-pycno meter shows that it differs in construction from the 
ordinary hydrometer chiefly in having a glass bulb, C, placed between 
the loaded bulb, F, and the expanded portion, B, of the stem; the bulb 
c is provided with a stopcock, d, and into it is poured the fluid to be 
tested ; the small glass knob, E, serves to balance the instrument when 
immersed in water, which should be at 17.5° C. (63.5° F.) ; the 
specific gravity is shown on the divided scale in the tube, A. The 
densimeter is chiefly intended to be used for oils and similar liquids 
lighter than water. The upper part of the tube, A to B, consists of a 
little cup of 1 Cc. capacity ; when floated iu water the instrument 
sinks to the point c, and when carrying 1 Cc. of water iu the cup it 
sinks to B. The space on the stem between B and C is divided into 
20 equal parts, each division corresponding to -fa Gm. or 0.050 Gm.; 
now, if 1 Cc. of oil of peppermint be poured into the cup and the 
instrument floated in water it will probably sink to the eighteenth 
division of the scale — hence 18 X 0.05 = 0.900, the specific gravity 
of the oil. 

Specific Gravity of Solids. 

The various methods for finding the specific gravity of solids are 
based upon the well-established principles that all bodies immersed 
in a liquid displace a quantity of that liquid equal in volume to the 
volume of the body immersed, and at the same time are buoyed up 
with a force equal to the weight of the liquid displaced. The upward 
pressure exerted by the liquid upon the body immersed causes the 
latter to appear lighter in weight, and is proportional to the density 
of the liquid ; the loss of weight, then, which a body seems to sutler 
upon immersion in any liquid, represents the weight of a volume of 
that liquid identical with the volume of the body immersed. As 
stated on page 45, pure water at 15.6° C. (60° F.)has been chosen as 
a standard of comparison for solids, and may be directly employed for 
the immersion of all bodies upon which no solvent effect is produced; 
in the contrary case, other liquids must be used, as will be shown 
later on. The specific gravity of any solid can be ascertained by the 
simple rule of three, provided the first three terms of the proportion 
are known, namely : first term, the weight of the liquid displaced ; 
second term, the weight of the solid in air; third term, the specific 
gravity of the liquid used for immersion. Whenever water is used 
for immersion, the simple division of the weight of the solid in air 
by the loss of weight in water (weight of water displaced) expresses 
the specific gravity of the solid, since the specific gravity of water is 
1.000. The methods for finding the specific gravity of solids may 
be divided as follows : 

1. For solids insoluble in, but heavier than water; 

2. For solids insoluble in, but lighter than water ; 



60 



GENERAL PHARMACY. 



3. For solids soluble in water, whether heavier or lighter than 
that liquid ; 

4. For solids in powder form. 

For solids insoluble in, but heavier than water, several methods 
are available ; of these, the direct method of weighing is the most 
accurate and generally employed. 

In place of the more expensive hydrostatic balance, any good 
sensitive prescription balance may be used ; the only extra piece 
necessary being a small wooden or stiff wire bench as a support for 
the vessel of water, as shown in Fig. 42. For instance, a piece of 



Fig. 42. 



Fig. 43. 





70 



50 



Diagram! showing the manner of weighing a solid body in a liquid. 

metal is found to weigh 258.75 grains in air; by 
means of a silken thread, or fine horse-hair, it is com- 
pletely immersed in pure water and found to weigh 
235.75 grains, the difference or loss of weight, 23 
grains, representing the weight of a volume of water 
equal in volume to the 258.75 grains of metal. 
Dividing 258.75 by 23, the specific gravity of the 
metal is found to be 1 1.25. 

Another but less accurate method is to weigh the solid in metric 
weight and then place it in a graduated cylinder containing sufficient 
water to submerge the solid completely (see Fig. 43); the difference 
between the first height of the water and that after immersion of the 



Graduated 
cylinder. 



SPECIFIC GRAVITY. 61 

solid indicates the volume of water displaced, and its corresponding 
weight is readily noted. Suppose a solid body weighing 7.5 Gm., 
placed into 40 Cc. of water, causes the latter to rise to 41.5 Cc, 
showing that 1.5 Cc. of water have been displaced, which weigh 1.5 
Gm.; then, applying the rule, 7.5 -f- 1.5 = 5, the specific gravity of 
the solid. 

Since solid bodies will float indifferently in any liquid having the 
same specific gravity as themselves, advantage may be taken of this 
property to determine the specific gravity of solids. Hager recom- 
mends determining the specific gravity of fats by placing them in 
alcohol and then adding water until the fat floats about indifferently 
beneath the surface of the mixture; the specific gravity of the mix- 
ture is then taken in the usual way, preferably by means of a pyc- 
nometer, and this at the same time expresses the specific gravity of 
the solid. 

To ascertain the specific gravity of solids insoluble in, but lighter 
than water, it becomes necessary to insure their immersion in water 
by attaching to them some heavy substance, the weight of which in 
water must previously have been ascertained. Upon immersing the 
two bodies in water it will be observed that the weight of the two 
appears less than the weight of the heavy body alone, which is due to 
the fact that the volume of water equal to the volume of the lighter 
body is heavier than the latter, and therefore exerts a greater up- 
ward pressure on the heavy body, causing it to appear to lose weight. 
The difference between the weight of the heavy body in water and 
the united weight of the light and heavy bodies in water expresses 
the excess of weight of a volume of water over the weight of a like 
volume of the light body ; in other words, it shows how much heavier 
a volume of water is than the same volume of the light body; to 
find the exact weight of a volume of water equal to the volume of 
the light body, this difference, or excess, must be added to the weight 
of the light body in air. Suppose a piece of cork weighs 62.5 grains 
in air; attached to a piece of metal which weighs 94 grains in water, 
the w r hole is found upon immersion in water to weigh 88 grains, or 6 
grains less than the metal alone; adding 6 to b'2.5 grains (the weight 
of the cork) we obtain 68. 5 grains, the weight of the water displaced 
by the cork. The specific gravity of the cork is found by dividing 
62.5 by 68.5 according to the general rule on page 46. The answer 
will be0.9124+. 

For solids soluble in water some other liquid must be selected for 
immersion, in which the solid body is perfectly insoluble and of 
which the specific gravity is known ; in other respects any of the 
preceding methods may be followed. In such cases the weight of 
the liquid displaced, having been ascertained, may be used to find the 
weight of a corresponding volume of water, and the latter then be 
divided into the weight of the solid; or the weight of the solid in air 
may be divided by the weight of the liquid displaced and the quotient 
then multiplied by the specific gravity of the liquid ; by either 



62 GENERAL PHARMACY. 

method the specific gravity of the soluble substance will be obtaiued. 
To find the weight of a corresponding volume of water, divide the 
weight of the liquid displaced by its specific gravity, for the weights 
of equal volumes of two bodies are to each other directly proportional 
as their specific gravities. Example: A piece of alum weighs 125 
grains in air; immersed in oil of turpentine having the specific 
gravity 0.860 it weighs 62 grains ; 125 divided by 63 (the loss 
of weight) yields 1.984; oil of turpentine weighing only 0.86 as 
much as water, 1.984 must be multiplied by 0.860, which gives 
1.7062-}- as the specific gravity of the alum. Or the weight of a 
volume of water corresponding to the volume of oil of turpentine 
displaced may be found by dividing 63 by 0.86, which equals 73.256, 
and this divided into 125, the weight of the alum in air, also gives 
1.7062+ as the specific gravity of the alum. 

Sometimes it is desirable to find the specific gravity of solids in 
powder form, as calomel, reduced iron, lead oxide, and the like ; this 
is best done by using a flask or bottle known to hold a definite 
quantity of water, introducing a certain weight of the powder, and 
then filling with water and weighing the total contents ; as two 
bodies cannot occupy the same space at the same time, it follows that 
the flask or bottle containing the powder cannot hold the same quan- 
tity of water as when empty, and this difference corresponds to the 
weight of water equal in volume to the powder. Suppose 100 grains 
of an insoluble powder are placed in a counterpoised 1000-grain 
bottle, the latter being then filled with pure water; if the total contents 
weigh 1088 grains, 12 grains of water have been displaced by the 
powder, for 1088 — 100 leaves 988, and, as the bottle is capable of 
holding 1000 grains of water, the difference 1000 — 988 = 12 must 
have been displaced. Then applying the rule, 8.333+ is found to 
be the specific gravity of the powder, as 100 s- 12 = 8.333 + . 

Specific Volume. 

The term specific volume is used to define the ratio existing be- 
tween the volumes of certain weights of bodies and the volume of 
the same weight of pure water ; it is therefore the opposite of specific 
gravity. Specific volume is ascertained by dividing the specific 
gravity of a body into unity, and hence may be called the reciprocal 
of specific gravity ; it may also be found by dividing the weight of 
a given volume of water by the weight of an equal volume of a 
liquid. Every pharmacist is aware that it will require vessels of 
different size to hold one pound of ether, water, glycerin, sulphuric 
acid, oil of turpentine, or chloroform, and it is often desirable to 
know in advance the volume of a given weight of a liquid ; the 
weight in grammes of any liquid multiplied by the specific volume, 
or divided by the specific gravity, of that liquid at once expresses the 
actual volume in cubic centimeters. To find the volume of a given 
weight, avoirdupois or apothecaries', of a liquid, it becomes necessary 



SPECIFIC GRAVITY. 63 

first to ascertain the volume of a like weight of water, and then to 
multiply this by the specific volume, or to divide by the specific 
gravity of the liquid ; or the given weight of a liquid may be divided 
at once by its specific gravity, which will yield the weight of a 
volume of water equal to the volume of the liquid, aud then by find- 
ing the volume of such a weight of water the volume of the liquid 
is at once known. 

Examples : If the volume of 500 Gm. of alcohol U.S.P. is 
desired, divide 500 by 0.820, the specific gravity of the alcohol, aud 
the quotient 609.75 -f- will be the answer in cubic centimeters. 

To find the volume of 8 ounces of official glycerin (apothecaries' 
weight) it is necessary to multiply by 480, the number of grains in 
1 ounce, and then divide the product by 455.7, the number of grains 
in one U. S. fluidounce of water, the quotient (480 X8 = 3840 ; 
3840 -v- 455.7 = 8.427), 8.427, represents the number of fluidounces 
contained in the same weight of water ; 8.427 then divided by 1.25, 
the specific gravity of the glycerin, yields 6.7416 fluidounces as the 
volume of 8 troy ounces of glycerin. 

How large a bottle is required to hold oue pound of chloroform 
of 1.490 specific gravity ? One pound avoirdupois is equal to 7000 
grains, and 7000 -r- 1.490 = 4697.986, the weight in grains of a 
volume of water equal to the chloroform; then 4697.986 -f- 455.7 
= 10.309, or very nearly 10J fluidounces. 

Adjustment of Specific Gravity and Percentages. 

While the adjustment of percentages in liquids as well as solids 
presents no difficulties, the reduction of liquids from a higher to a 
lower specific gravity is not quite so easily accomplished, since 
specific gravity is but the expression of the relation between volume 
and weight, and condensation of volume frequently occurs as the 
result of a mixture of two liquids. Two very simple rules, or 
formulas, have been published for the adjustment of specific gravities 
of liquids, by volume and by weight; but absolutely accurate results 
are only possible when no contraction of volume takes place ; in the 
majority of cases the condensation of volume is but very slight, and 
for ordinary purposes may be ignored. It is well known that the 
weights of equal volumes of two liquids are to each other directly 
proportional as the specific gravities of these liquids ; therefore, the 
weight of a liquid divided by its specific gravity represents a weight 
of water equal in volume to the weight of that liquid. It is also 
well known that the volumes of equal weights of two liquids are 
to each other inversely proportional as the specific gravities of these 
liquids ; therefore, the volume of a liquid multiplied by its specific 
gravity represents a volume of water equal in weight to the volume 
of that liquid. The well-known process of alligation is admirably 
adapted to the adjustment of specific gravities of liquids by volume, 
but is unsuited to adjustment by weight. When two liquids of 



1.520 
1.387 

1.280 



64 GENERAL PHARMACY. 

different specific gravities are mixed, the loss which one suffers will 
be balanced by the gain of the other ; hence, the two liquids used 
must be mixed in inverse proportion to that existiug between the 
gain and loss of specific gravity aud the specific gravity of the 
mixture ; the difference between the higher specific gravity and the 
desired specific gravity of the mixture will therefore indicate the 
proportiou of the liquid having the lower specific gravity ; aud the 
difference between the lower specific gravity and the desired specific 
gravity will indicate the proportion of the liquid having the higher 
specific gravity. For example, if solution of ferric chloride, specific 
gravity 1.520, is to be reduced to 1.387 specific gravity by addition 
of a weaker solution of 1.280 specific gravity, 107 volumes of the 
stronger must be mixed with 133 volumes of the weaker solution, 
or, in other words, 1 volume of the former with 1.243 volumes of 
the latter. It is customary to set down a problem in alligation in 
the following manner to facilitate comparison : 

0.107 = proportion of the stronger liquid. 

0.133 = proportion of the weaker liquid. 

If a definite volume of the mixture is desired, the requisite volume 
of the stronger and weaker liquids may be ascertained by dividing 
the desired volume by the sum of the proportionals, and then mul- 
tiplying each proportional by the quotient so obtained ; thus, if 32 
fluidounces are wanted, divide 32 by 0.240 (0.107 + 0.133), which 
yields 133.3 ; 0.107 X 133.3 = 14.27 fluidounces, the requisite volume 
of the stronger solution, and 0.133 X 133 3 = 17.73 fluidounces, the 
requisite volume of the weaker solution. 

To adjust the specific gravity of a given weight of a liquid to a 
higher or lower specific gravity, the following formula may be 
employed : 

w X c (a — 6) 

a (b — c) 

in which x represents the weight of the diluent, w the weight of the 
liquid to be diluted, a the specific gravity of the liquid to be diluted, 
b the desired specific gravity, and c the specific gravity of the diluent. 
(Whenever water is the diluent, c is made 1.000.) As stated before 

(see page 63), — = weight of water equal in volume to w, — ===. weight 

of water equal in volume to x, — r — = weight of water equal in 

volume to id + x. To find the value of x, the following equation, 

10 x w + x 

— 4- — = — 7 — , must be solved : 

a c b > 

web -j- abx = wac -\- acx 

abx — acx = wac — web 

x>(a(b — c) = it;X c ( a — b) 

iv X c(a — b) 

a(b — c) 



SPECIFIC GRAVITY. 65 

Example : How much water must be added to 250 Gm. of solu- 
tion of potassa of 1.589 specific gravity in order to reduce the specific 
gravity to 1.036? Substituting numerical values for the letters 

250x1.000(1.539 — 1.036) 
iu the above formula, Ave have x = — i ^q c\ n^K 1 0(Ti ' 

250 X 0.503 125.75 

then 1.539 X 0.036 = 0055404 =2269.6. Answer : 2269.6 Gm. 

To make a definite weight of a liquid of definite specific gravity 
by mixing two liquids of known specific gravity, both being of the 
same kind, or one being water : 

Let miv represent the desired weight of the mixture, x the weight 
of the diluent, y the weight of the liquid to be diluted, and a, b, c 
the specific gravity of the liquid to be diluted, of the mixture 
desired, and of the diluent respectively. (Whenever water is the 
diluent, c is made 1.000.) Since x + y = mw, and the value of x 

the liquid to be diluted X c (a — b) 

has been shown above to be - — 77 v — — — , the 

a(p — c) 

latter expression may be substituted for x in the equation, x -f y = 

y X c(a — 6) 
miv, thus — ,, v — + V = mw - This simplified is yea — yeb + 

yab — yac = mw X a (b — c), and cancelling, y X b (a — c) = mw X 

a (b — c). 

mw X « (l> — c ) 

V ~ b{a — c) 

The value of y (weight of stronger liquid) having been ascertained, 
it is subtracted from mw, the desired weight of the mixture, to find 
the value of x, the weight of the diluent. 

Example : If it is desired to make 10 pounds of ammonia water 
of 0.960 specific gravity, from ammonia water of 0.900 specific 
gravity, mix 3.75 pounds of the latter with 6.25 pounds of water ; 
for, substituting numerical values for the letters in the above 
formula, the weight of the liquid to be diluted is equal to 
IPX .900( 0.960 — 1.000) 10 X — 0. 036 —0.36 

0.960(0.900 — 1.000) ~~ —0.096 ~~ — 0.096 ~~ 3,7D? 
and .10 — 3.75 = 6.25. 

For the adjustment of percentage in alcohol (by weight or volume), 
in acids (by weight), and in alkali solutions (by weight), the follow- 
ing rules may be applied : 

For reducing solutions from a higher to a lower percentage : 
Multiply the given quantity by the given percentage and divide by the 
required percentage; the quotient will be the quantity to which the 
liquid must be diluted by the addition of water. Since alcohol is fre- 
quently reduced in volume percentage, and contraction of volume 
invariably follows the admixture of alcohol and water, it becomes 
necessary, after contraction has ceased, to add sufficient water to 
restore the original volume of the mixture. 



QQ GENERAL PHARMACY. 

Examples : Keduce 4 pints (64 fluidounces) of 93 per cent, (by 
volume) alcohol to 65 per cent. : 64 X 93 = 5952, and 5952 -f- 65 
= 91.57. Enough water must be added to the 4 pints of alcohol 
to yield, after contraction has ceased, 91,57 fluidounces. 

Reduce 2 pounds of hydrochloric acid from 31.9 per cent, to 10 
per ceut. : 2 pounds = 32 avoirdupois ounces ; 32 X 31.9 = 1020.8, 
aud 1020.8 -=- 10 = 102.08. Enough water must be added to the 
2 pounds of acid to bring the total weight up to 102.08 avoirdupois 
ounces. 

Reduce 8 troy ounces of stronger ammonia water, 28 per cent., to 
10 per cent, strength : 8 X 28 = 224, and 224 -*- 10 = 22.4. Enough 
water must be added to the 8 troy ounces of stronger ammonia water 
to bring the total weight up to 22.4 troy ounces. 

For making a definite quantity of a solution of a certain percent- 
age by diluting a stronger solution with water : Multiply the required 
quantity by the required percentage, and divide by the higher percent- 
age ; the quotient loill be the quantity of the stronger liquid necessary, 
and this subtracted from the total quantity required leaves the necessary 
quantity of water. When volume adjustment of alcohol is made, 
the same precautions iu regard to contraction of volume must be 
observed as stated in the preceding rule. 

Examples : Make 1 gallon (128 fluidounces) of 60 per cent, (by 
volume) alcohol from alcohol of 94 per cent, (by volume) : 128x60 
= 7680, aud 7680-*- 94 = 81.7. Answer: 81. "7 fluidounces of the 
stronger alcohol must be mixed with sufficient water to yield, after 
contraction has ceased, 128 fluidounces. 

Make 4 pounds of 25 per cent, phosphoric acid from the official 
85 per cent, acid: 4 pounds =64 av. ozs. ; 64X25 = 1600, and 
1600 -f- 85 = 18.823. Answer : Enough water must be mixed with 
18.823 av. ozs. of the strong acid to bring the total weight up to 64 
av. ozs. 

Make 720 grains of 5 per cent, caustic potash solution from a 12.5 
per cent, solution : 720X5 = 3600, and 3600--- 12.5 = 288; 720 — 
288 = 432. Answer: 288 grains of the 12.5 per cent, solution must 
be mixed with 432 grains of water. 

The adjustment of percentage in liquids may also be readily made 
by the process of alligation, as already explained under adjustment of 
specific gravities by volume, page 64. 

Pharmacists and drug jobbers are sometimes called upon to make 
mixtures of certain liquids or solids having different percentage 
strengths in order to produce a desirable average strength ; this may 
be done by the general rule for alligation. Write the percentages in 
a column, and the mean percentage on the left. Connect the simples 
in pairs, one less than the mean with one greater ; take the difference 
between the mean and the numbers representing the percentage 
strength of each simple and write it opposite the value with which 
it is linked. These differences are the relative quantities of the sim- 
ples taken in the order in which their values stand. 



SPECIFIC GBA YITY. 



67 



Example: In what proportion must powdered opium of 9, 12.5, 
1 5, and 1 6 per cent, morphia strength be mixed to produce a mix- 
ture of 14 per cent, strength ? 



14 



9.0— i 


12.5- -j 


15.0-1 


16.0 



1.0 
2.0 
5.0 
1.5 



Proof. 
X 9 = 9 

X 12.5 = 25 



1 
2 
5 X15 =75 

1.5X16 =24 



or 14 



9.0— 
12.5- 
15.0- 
16.0— 



Proof. 

2.0 2 X 9 = 18 

1.0 1 X 12.5= 12.5 

1.5 1.5X15 = 22.5 

5.0 5 X16 = 80 



9.5 



133 
14 



\.H 



) 133.0 
14 



Auswer : 1 part of 9 percent., 2 parts of 12.5 per cent., 5 parts of 
15 per ceut., and 1.5 parts of 16 per cent., or 2 parts of 9 per cent., 
1 part of 12.5 per cent., 1.5 parts of 15 per cent., and 5 parts of 16 
per cent. 

It matters not how the simples are connected, as long as one less 
than the mean is compared with one greater, for while the propor- 
tional part of each simple may vary, the sum of the proportionals 
remains the same. If the number of simples is not evenly divided 
among those less and those greater than the mean, two or more of the 
former may be linked with one of the latter, and vice versa; thus, to 
mix 7, 8, 9, and 28 per cent, ammonia water so as to produce 10 per 
cent, ammonia water, it would be necessary to use 6 parts of the 28 per 
cent, solution and 18 parts each of the 7, 8, and 9 per cent, solutions. 



10 



■, 9 -| 
| 28= 



18 
18 
18 

3+2+1=6 


Proof. 

18 X 7 = 126 

18 X 8 = 144 

18 x 9 = 162 

6 X 28 = 168 




(iit ) 600 




10 



If a definite quantity of one of the simples be directed to be used 
in the mixture, the corresponding quantities of the others are readily 
ascertained by multiplying their proportionals by the ratio which the 
given quantity bears to the proportional of the simple which it 
represents. 

Example : How much powdered cinchona bark containing 3, 3.5, 
6, and 6.5 per cent, total alkaloids must be mixed with 10 pounds 
of cinchona bark containing 4 per cent, total alkaloids to produce a 
mixed powder of official strength, 5 per cent, total alkaloids. 



10 



10, ratio of given quantity to proportional. 



3.0 




1.5 


3.5 




1.5 


4.0- | 




1.0 


6.0- | 




(].o 




2.0+1.5 = 3 



68 



GENERAL PHARMACY. 



Answer. 




Proof. 




1.5 X 10 = 15 pounds of 3 % 


bark. 


15 X 3 = 


45 


1.5X10 = 15 " " 3.5 " 


a 


15 x 3.5 = 


52.5 


1.0X10 = 10 " " 4 " 


a 


10 X 4 = 


40 


1.0X10 = 10 " " 6 " 


it 


10X6 - 


60 


3 5X10 = 35 " " 6.5 " 


n 


35 X 6.5 = 


227.5 






85 ) 


425.0 



If a definite quantity of a mixture is required, the quantity of each 
simple may be ascertained by multiplying its proportional by the ratio 
which the total quantity required bears to the sum of the propor- 
tionals of all the simples. 

Example : How many grammes of powdered opium of 9, 12, 
15, 16, and 17 per cent, morphia strength must be taken to produce 
250 grammes of a mixture containing 14 per cent, of morphia. 



14 



5 X 13.89 = 69.45 
1 X 13.89 = 13.89 
2X13.89 = 27.78 
5 X 13.89 = 69.45 
5 X 13.89 = 69.45 



250 -s- 18 



18 the sum of proportionals 250.02 

13.89, ratio of required quantity to the sum of the proportionals. 



Answer : 69.45 Gm. each of 9 per cent., 16 per cent., and 17 per 
cent, opium, 13.89 Gm. of 12 per cent, opium, and 27.78 Gm. of 15 
per cent, opium. 

The foregoing rule can also be applied to a mixture of liquids of 
different specific gravities. 

Example : A pharmacist is called upon to prepare 500 Cc. of a 
mixture of alcohol, spec. grav. 0.820; glycerin, spec. grav. 1.25; 
simple syrup, spec. grav. 1.317 ; and water; the mixture to contain 15 
per cent, by volume of glycerin, and to have the same specific gravity 
as water. How will he proceed ? 

The 500 Cc. of mixture must weigh 500 Gm. in order to have the 
same specific gravity as water; 15 per cent, of 500 is 75, and 75 Cc. 
of glycerin of 1.25 specific gravity will weigh 93.75 Gm. ; this 
leaves 425 Cc. as the volume of the alcohol, syrup, and water mix- 
ture, the weight of which must be 500 — 93.75 = 406.25 Gm. Such 
a mixture would have the specific gravity 0.9559, for 406.25-^425 
= 0.9559, and the necessary quantity of each ingredient may be 
ascertained by alligation, thus 



0.9559 



0.820=^ 
1.000-1 
1.317— 



0.0441 -f 0.3611 



0.4052 proportional of alcohol. 
1359 " " water. 

0.1359 " " simple syrup. 



0.6770 sum of the proportionals. 
425 -r-' 0.6770 = 627.8, ratio of required quantity to the sum of the proportionals. 
627.8 X 0.4052 = 254.384 Cc. of alcohol.' 
627.8 X 1 359 = 85.318 Cc of water. 
627.8 X 1.359 = 85.318 Cc of syrup. 



SPECIFIC GBA VITY. ft 9 



Cc. 




Proof 






254.384 


@ 


0.820 


= 


208.594 




85.318 


u 


1.000 


= 


85.318 




85.318 


a 


1.317 


= 


112.363 




75.000 


u 


1.250 


) 


93.750 




500.020 


500.025 


( 1.000 



Answer: 75 Cc. of glycerin must be mixed with 85.318 Cc. each 
of simple syrup and water, and 254.384 Cc. of alcohol. No allow- 
ance has been made for contraction of volume, which is sure to follow ; 
hence the final volume of the mixture will be slightly below 500 Cc. 
and the specific gravity slightly above 1.000. 



CHAPTEK IY. 

HEAT. 

One of the most valuable aids to the pharmacist in the numerous 
manipulations of the store and laboratory is heat ; hence a knowl- 
edge of its varied application and the modes of controlling and 
directing its influence is necessary. 

The undulatory theory regarding heat is now accepted by all scien- 
tists ; this declares heat to be a force generated by the motion of the 
molecules of bodies, and that it is the increase or decrease of this molec- 
ular energy that gives rise to the conditions designated as hot, warm, 
and cold. No body is entirely without motion of its molecules, hence 
the terms heat and cold are merely relative ; moreover different bodies 
have different capacities for heat, as is clearly proven by two persons 
entering the same apartment, one of whom may complain of uncom- 
fortable warmth, while the other experiences a chilly sensation. The 
chief effect of heat, or increased molecular motion, is to overcome the 
force of cohesion and expand the volume of bodies by increasing 
the intermolecular spaces ; the three states of aggregation, known as 
solid, liquid, and gaseous, being the result of cohesive force, are, 
therefore, dependent upon the amount of heat generated in or applied 
to a body. 

All solid bodies, when their molecular motion has become suffi- 
ciently intensified, will become luminous, as is shown by the spark 
emitted when steel and flint are struck together, or by the kindling 
of flame when two pieces of dry wood are rubbed together vigorously 
for some time. 

Oftentimes the luminosity of heated bodies is used to indicate the 
degree of heat exhibited ; hence such terms as dull-red heat, cherry- 
red heat, and white heat, of which the first named is produced during 
ordinary combustion of fuel in a stove, without a strong draught of 
air, while the last-named is the result of most intense activity in 
molecular motion, brought about by the aid of a powerful air-blast 
in the combustion of fuel or by the use of electric currents. 

Heat may be either active or latent; the former increases the 
temperature of bodies and causes their expansion, while the latter is 
heat hidden, after the expansion has been effected, for the purpose of 
keeping up the expansion. Active or sensible heat can be measured 
by its effect on mercury, upon which latent heat makes no impression ; 
the latter can be converted into the former, however, by pressure and 
other agencies. 

Heat is in almost daily use by the pharmacist in the operations of 



HEAT. 71 

solution, fusion, evaporation, and decoction, and may be applied 
either by direct contact with the burning fuel or through the agency 
of some interposed medium. The use of coal as a fuel for the pro- 
duction of steam is confined to manufacturing establishments, the 
retail pharmacist fiuding illuminating gas or some of the various 
kinds of coal-oil better adapted to his wants. Wherever illuminat- 
ing gas is available it is decidedly the most desirable fuel at the 
present day, not only because its supply is constant, but also because 
with modern apparatus and appliances it cau be kept completely 
under control, and thus the greatest amount of heating power be 
obtained at a minimum of cost. In the course of time electricity 
will no doubt become a serious competitor of gas for heating purposes 
in pharmaceutical laboratories, as its use in the arts and for domestic 
purposes has already demonstrated. Fig. 44 illustrates an electric 
plate-stove, simple in construction and very convenient for boiling 
and distilling inflammable liquids. 




Electric plate-stove, showing switch for regulating the current. 

Gasoline vapor and kerosene are extensively employed for the 
generation of heat, in localities where illuminating gas cannot be 
procured ; although both are quite cheap in price, a certain element 
of danger attends the use of the former, while the latter is open to 
the objections that it cannot be burned without the aid of a wick, 
that it deposits soot unless the wick is carefully watched, and that 
its combustion is frequently accompanied by a more or less disagree- 
able odor. For small operations alcohol offers an excellent fuel of 
good heating capacity ; its high price forbids its more extensive use. 

The amount of heat produced by the combustion of any particular 
fuel is constant, no matter how the combustion is effected ; but the 
intensity of heat is dependent upon the rapidity of combustion ; there- 
fore, the finer the division of the fuel, the more rapidly will it be 
burned or oxidized, and consequently the greater will be the degree 
of heat generated. 

Various appliances have been designed for the production of heat 
for pharmaceutical purposes, of which a few are shown herewith, as 
it is assumed that either gas or coal-oil is available everywhere. 

When the price of alcohol is not an object, this fuel is preferable 



72 



GENERAL PHARMACY. 



to coal-oil where illuminatiDg gas is Dot available. Fig. 45 repre- 
sents a very convenient form of spirit lamp, nickel-plated and pro- 
vided with a regulating screw for the wick ; it is not easily upset 
aud answers well for small operations at the dispensing counter. 



Fig. 45. 



Fig. 46. 





Barthel's alcohol lamp. 



Fig. 4Tt 



Nickel spirit lamp. 

Barthel's alcohol lamp, Fig. 46, 
was introduced in Germany in 1891, 
and is capable of producing an in- 
tense heat by the combustion of 
alcohol vapor. This lamp, which is 
perfectly safe, is extensively used 
in Europe ; it is made of metal, 
has a lateral capped orifice for fill- 
ing, and bears a central tube, closed on top, which carries a solid 
wick. This is not itself ignited, but only serves to draw up alcohol 
from the reservoir. To the wick-tube is attached a second tube, the 
burner-tube proper, which receives the vapors from the wick. The 
burner-tube contains a wire diaphragm, which 
can be raised or lowered by means of the 
regulating screw, and thus a higher or lower 
flame obtained as desired. When the lamp 
is to be used, the wick-tube must be heated 
slightly by means of a lighted match, so as 
to drive some alcohol vapor into the burner- 
tube, where it is then ignited. It will then 
continue to draw up alcohol vapor of its own 
accord. The efficiency of the lamp is shown 
by the fact that a quart of water can be raised 
from 60° F. to the boiling-point in eight and 
three-quarter minutes, with an expenditure 
of about one ounce of alcohol ; low-grade 
alcohol of 75 or 80 per cent, evaporates less 
rapidly than stronger alcohol and produces equally good results. 

For the combustion of coal oil, stoves are now manufactured 
which are claimed to produce a smokeless and odorless flame ; the 
heating capacity of these stoves is quite considerable, and is regulated 
by means of screws for raising and lowering the wick. Fig. 47 




Whitney's coal-oil stove. 
(Single burner.) 



HEAT. 



73 



represents the Whitney Patent Hot-blast Stove, in which the wick 
chamber is separate from the oil reservoir. Coal-oil stoves may be 
had with one, two, or three wicks, and require some attention, so that 
the wicks shall always be kept well trimmed and free from carbona- 
ceous matter ; to avoid a deposit of soot, the wick should never be 
allowed to touch the vessel to be heated. 

It is well known that the illuminating power of gas depends upon 
the incandescence of particles of unconsumed carbon, and that if these 
particles be brought to complete combustion by the appropriate use of 
air (atmospheric oxygen), the luminosity of the flame will be decreased, 
but its heating power will be intensified. A yellow carbonized flame, 
also known as oil flame, because resembling that produced by the 
combustion of oil, is never well adapted for heating purposes, besides 



Fig. 48. 



Fig. 49. 




Fletcher low-temperature 
burner. 




Foot-blower. 



depositing considerable soot or carbon on the bottom of vessels 
placed over it. In all modern gas-heating apparatus, proper pro- 
vision is made for mixing the illuminating gas with such a propor- 
tion of air that, when the mixture is iguited, a purely blue flame will 
result, indicative of complete combustion ; burning alcohol resembles, 
such a flame. A large variety of gas burners and stoves is now 
offered, intended to furnish both high and low powers of heat. Of 
these probably none has a wider range in heating capacity than the 
Fletcher low-temperature burner (Fig. 48), any degree of heat from 
a gentle current of warm air to clear red heat being obtainable ; it is 
manufactured by the Buffalo Dental Manufacturing Company, of 
Buffalo, X. Y. The burner consists of a ring of iron tubing, D, 
perforated on the upper side, and enclosed in a cylinder of cast 
iron, over which a diaphragm of wire gauze, A, is fastened ; there 
is a space, B, between the low r er end of the cylinder and the bottom 
of the apparatus, for the admission of air, and a tube, c, for the 
attachment of a pipe from a bellows when a blast is to be used for 
producing powerful heat. When a gentle heat is desired, the gas is 
lighted through the opening B, thus heating the air as it flows up- 



74 



GENERAL PHARMACY. 



ward and escapes through the gauze A. For a stronger heat the gas 
and air mixed are lighted above the wire gauze, and a steady, smoke- 
less, blue flame is thus obtained. As any rubber tubing attached to 
D is apt to become very hot, it should either be wrapped with a small 
wet cotton cloth, dipping in water, or, what is still better, about 
eight inches of gas-pipe should be permanently attached to D, to 
which the rubber supply-tube may be secured when wanted. Fig. 49 
represents a convenient foot-blower for use with any gas furnace requir- 
ing a strong supply of air ; the rubber disk is well protected by netting. 
For small operations at the dispensing counter, Bunsen burners are 
usually employed, which are so constructed that a small supply of 
gas is made to yield a strong heat by admixture with air, whereby 
perfect combustion is effected. One drawback to the majority of 
Bunsen burners in the market is the tendency to " light back " — that 
is, when the flame is reduced, it is apt to recede and ignite the gas 
at the pinhole orifice in the tube; the most effectual method of 
overcoming this difficulty is to contract the orifice of the tube and 
introduce a gauze diaphragm into it near the top, which, how- 
ever, reduces the heating power of the flame. Among the large 
variety of Bunsen burners sold, a few have been found specially 
adapted to the use of the pharmacist, and are here illustrated. 
Fig. 50 represents a low form of burner, 3 inches high, made in 



Fig. 50. 



Fig. 51. 




Bunsen burner, low form with crown. 



tw T o sizes, with tubes of T 5 g- and -| 





The Acme safety burner. 



inch in diameter respectively; with 
the aid of a contracted brass cap, 
the flame can be turned down quite 

low without receding. When it is desired to distribute the flame, the 
brass crown shown in the cut should be attached, after removal 
of the brass cap; the crown, being provided with three supports, 
does away with the necessity for a tripod. The burner is made 
by Bullock & Crenshaw, of Philadelphia, and will be found very 



HEAT. 



75 



Fig. 52. 



serviceable for all smaller operations. In Fig. 51 is shown the 
Acme Burner, patented in 1891 by T. Boyce, of New York ; this 
is probably the most satisfactory burner made for small operations 
at the dispensing counter, and can be used for coal or gasoline gas. 
Each burner is provided with two tubes, one of the regular Bunsen 
pattern, the other with a gauze safety-tip (Fig. 52), permitting the 
flame to be turned down as low as desired, and out without receding. 
The supply of gas is regulated by turning the 
tube at a until the desired quantity of flame is 
obtained ; by turning the milled disk, B, up or 
down, it being threaded and moving upon the 
nipple, the air-supply is adjusted. The height of 
the burner is 5 J inches, including the base. The 
Finkner burner (Fig. 53) yields a very satisfac- 
tory flame, but is not adapted for very strong 
heat ; it is so constructed that the supply of gas 
and admixture of air can be simultaneously regu- 
lated by turning the milled head. Fig. 54 rep- 
resents a convenient adjustable burner ; by turning 
the screw, which is accessible to the fingers while 
the burner is in use, the gas orifice can be so 
adjusted that any desired flame may be had. The 
air-supply is adjusted by turning the air- regulator 
up or down, it being threaded and moving upon 
the burner tube. The moving of the point up 
through the gas orifice, while reducing the gas quantity and size of 
the flame, does not reduce the gas pressure; the gauze safety-tip 




Gauze tip and tube for 
the Acme burner. 



Fig. 53. 



Fig. 54. 




The Finkner burner. 




Adjustable Bunsen burner. 



(Fig. 52) can also be attached to this burner when a very small 
flame is desired. For maintaining low temperatures, as in the 



76 



GENERAL PHARMACY. 



testing of pepsin and similar operations, the double minim burner 
(Fig. 55) will be found useful. 

For use with inflammable liquids the apparatus illustrated in Fig. 
66 will be found serviceable, the burner being surrounded with safety 



Fig. 55. 



Fig. 56. 




Double minim burner. 

gauze, which prevents the flame 
from communicating with the 
vapor on the outside, the principle 
being the same as in the Davy 
safety lamps. 

Fletcher's radial burner (Fig. 
57) possesses some advantages over 
other heaters, in containing no 
loose parts and in being made en- 
tirely of annealed cast-iron ; it 
is practically indestructible ; if 
choked with dirt it is readily 
cleaned with a card or spatula. 
The flames are practically solid 
when in use, and show no ten- 




Safety burner, to be used for heating inflam- 
mable liquids. 



Fig. 57. 




Fletcher's radial burner. 



dency to run to a point in the centre ; the consumption of gas 
amounts to from 12 to 18 feet per hour, and the burner will accom- 
modate vessels from 10 to 18 inches in diameter. 



HEAT. 



77 



Fig. 58. 



For larger operations the " Jewel " gas-stove, Fig. 58, manufac- 
tured by Geo. M. Clark & Co., Chicago, will be found very serviceable. 
The cast-iron frame is twelve inches square 
and five inches high, thus standing very 
firm and capable of supporting large 
vessels. The gas is properly mixed with 
air before it enters the radial burner, where 
perfect combustion is effected, as shown by 
the pale-blue flame, which can be turned 
down very low without flickering. It con- 
sumes about eight feet of gas per hour, and is a most efficient heater. 

For regulating the degree of heat within certain narrow limits, 
special appliances have been devised, known as thermostats, by means 




Jewel gas stove. 



Fig. 59. 



Fig. 00. 





Reichert's thermostat. 



The Bunsen-Kenip gas regulator or thermostat. 



78 



GENERAL PHARMACY. 



of which the supply of gas admitted to the burner is automatically 
controlled by expansion and contraction of mercury contained in 
glass cups or tubes kept in contact with the air or liquid the tem- 
perature of which it is desired to maintain at, or near, certain points. 
All gas supplied to the burner is made to pass through the thermostat, 
and the required temperature having been reached, the gauge is set 
by means of a screw, after which the supply of gas is controlled by 
the expansion of the mercury caused by an increase of heat. Figs. 
59 and 60 show two thermostats frequently employed. 

The steam boiler, Fig. 61, designed by Prof. E. L. Patch, is a 



Fig. Gl. 




Prof. Patch's steam boiler. 



most convenient source of heat for the requirements of a small labo- 
ratory. The boiler, 22 inches high and 10 inches in diameter, is 
made of steel, contains 20 flues, and is covered with a thick layer of 
asbestos composition, to prevent loss of heat by radiation ; it has 
a capacity of 7 gallons and possesses one great advantage — that 
it can be heated by means of either a gas or a coal-oil stove. 
Being provided with a water-gauge, safety-valve and manometer, 
the boiler is as complete as any of larger size, and steam can be 
carried from it to any point desired ; it is usually filled from above 
at the safety-valve, but, wherever water service is available, an 
injector may be attached, so as to allow of filling while steam pres- 



HEAT. 



79 



sure is on. The coil of pipe in the conical ly shaped metal case on 
the side, may be used for hot filtration, evaporation or drying pur- 
poses. 

It is well known that steam, when confined, is capable of absorb- 
ing large quantities of heat, and its temperature rises proportionally 
to the pressure exerted upon it; dense aqueous solutions, therefore, 
can readily be boiled by means of superheated steam. 

For the proper control and distribution of heat, different devices 
are employed. When direct flame is to be applied to porcelain or 
glass vessels the interposition of wire-gauze or asbestos cloth will be 
found very desirable ; for not only will the heat be supplied to a 
greater extent of surface by radiation, but at the same time it will 



Fig. 62. 



Fig. 63. 




Sand-bath, shallow form. 




Sand-bath, deep form. 



be uniformly distributed, and thus insure more regular heating, which 
of itself is very important, considering the frail character of flasks 
and dishes. 

The sand-bath is employed for temperatures above that of boiling 
water, and is chiefly intended to maintain a continuous supply of high 



Fig. 64. 




(3 



g) 



Large sand-bath, heated by steam. 



heat and to prevent sudden depression of temperature from foreign 
causes ; it is invaluable in the distillation of certain liquids (acids, etc.) 
from glass vessels, and may be either of deep or shallow form. (See 



80 



GENERAL PHARMACY. 



Figs. 62 and 63.) The deep sand-bath consists of an iron pot or 
basin containing sufficient dry fine sand so that, if desired, the retort 
or flask may be entirely surrounded by the same. The best shallow 
sand-baths are made of Russian sheet-iron, and are well adapted for 
heating flasks and beakers, which require only sufficient saud to form 
a good bed of support, since an excessive amount would involve a 
waste of heat. 

For use in a laboratory where steam is available, a permanent 
sand-bath may be provided as shown in Fig. 64. It is constructed 
from an ordinary gal vani zed-iron sink and large gas-pipe, about 
three-quarters to one inch in diameter, arranged horizontally in folds, 
the ends of the pipe being introduced through holes of appropriate 
size drilled in the end of the vessel. Sand to the depth of two or 
three inches may be poured over the pipes, which will form an ex- 
cellent bed for flasks, dishes, and beakers. 

Other apparatus for the use of heat above that of boiling-water, 
yet avoiding contact with flame direct, are oil-baths, saline solu- 
tion baths, glycerin baths, or paraffin baths ; these are constructed 
like water-baths, and readily furnish temperatures rangiug from 100° 
to 300° C. (212° to 644° F.). 

For all operations requiring a degree of heat below that of boiling- 
water, water-baths will be found indispensable ; they may be made 
with either a round or flat bottom, as shown in Figs. 65 and 66 , and 



Fig. 66. 



Fig. 65. 





Round-bottom water-bath. 



Flat-bottom water-bath. 



provided with a set of concentric rings to adapt them for use with 
dishes or flasks of various sizes. Water- baths made of extra heavy 
tin will last a long time (provided they be dried properly afteruse), and 
do not cost much, while copper is far more expensive, but, on the other 
hand, resists the action of heat and water better than tinned iron. As 
long as the vapor of boiling water is allowed to escape freely, no amount 
of heat applied to the vessel can possibly increase the heat of the 
water above that of boiling, and, as some heat-power is lost during 
transmission from the water-bath to the vessel resting upon it, the 
liquid contained in such vessel will always be found a few degrees 
lower in heat than the water in the bath ; under no circumstances 
can aqueous liquids be made to boil in dishes placed in water-baths. 



HEAT. 



81 



The name vapor- bath is in the majority of cases more appropriate 
than water- bath, since the vessel heated by it does not, as a rule, 
come in contact with the water for any length of time, but derives 
its heat from the vapor or steam rising from the water and not con- 
fined by pressure. 

To avoid frequent refilling and consequent interruption in long- 
continued operations, water-baths are often provided with a constant 
supply attachment as shown in Fig. 67, which also serves to keep 



Fig. 67 




Water-bath with constant-level attachment. 



the water at a constant level in the bath. The best contrivance for 
a constant water-bath is that suggested by Dr. B. F. Davenport, of 
Boston, and shown in Fig. 68. It consists of a copper box, J., 10 or 
15 inches square, the top being a brass plate -| inch thick, to enable 
it to bear considerable weight without yielding. From the point B 
projects a J inch brass tube, B C, which turns up at a right angle. 
At E is a stopcock which is conuected by a thick rubber tube with 
the glass tube, D F, the latter being fastened against the adjoining- 
wall. Connected with C by a rubber tube-joint is a J inch block 
tin tube of 20 feet length, which extends up the wall, to which it is 
fastened for 10 feet to the point T, whence it returns and ends just 
over the top of the glass tube at D. The bath is filled w r itk water 
(preferably distilled) to just the level, B. .b. The steam generated by 
the constant boiling is condensed in the tube, C T D, either before 
or after reaching the top, T, and returns to the bath at C or at 
D, where it drops into the glass water-gauge, D F. Having once 
been filled, the water need not be replenished for years, and there 
being no outlet for the steam, except into the condensing tube, the 
air surrounding the water-bath will be kept constantly dry — a very 

6 



82 



GENERAL PHARMACY. 



Fig. 68. 



desirable point in the evaporation of liquids. If the water-bath is 
desired for use at fixed temperatures a thermometer may be intro- 
duced through a cork fitted to 
a tube inserted in the cover 
of the bath. 

The boiling-point of a liquid 
is that at which the elas- 
ticity of its vapor overcomes 
the pressure of the surround- 
ing atmosphere, or, in other 
words, beyond which the 
liquid cannot contiuue as a 
liquid without increased pres- 
sure. JSTormal atmospheric 
pressure, 15 pounds to the 
square inch, which is equal 
to the pressure of a column 
of mercury 760 Mm. (29.87 + 
inches) in height, is always 
assumed when referring to the 
boiling-point of a liquid, for 
any modification of the former 
will change the latter ; thus 
water, which ordinarily boils 
at 100° C. (212° F.), has 
been known to boil at 84° C. 
(183.2°F.) on Mont Blanc, in 
Switzerland, and even at 35° 
C. (95° F.) in a vacuum ap- 
paratus ; while, under greatly 
increased pressure, as in Pa- 
pin's digester, it has been 
heated to 160° C. (320° F.) 
without boiling. There exists 
also a great variability in 
the boiling-points of different 
liquids under normal condi- 
tions ; for, while official ether 
boils at about 37° C. (98.6° 
F.), chloroform requires a tem- 
perature of 60.5° C. (140.9° 
F.), alcohol 78° C. (172.4° 
and mercury about 357° C. 




Davenport's constant water-bath. 



F.), glycerin 165° C. (329° F.) 
(674.6° F.). 

The simplest method for determining the boiling-point of a liquid 
is to introduce some of it into a flask provided with a lateral tube in 
the neck and a thermometer passing through the cork, as shown in 
Fig. 69, or into an ordinary Florence flask provided with a doubly- 



HEAT. 



83 



perforated cork, through one orifice of which a thermometer is inserted 
and through the other a bent glass tube, as represented iu Fig. 70. 
If inflammable or uoxious vapors are likely to be evolved, the tube 
from either flask may be connected with a condenser. It is important 
that the thermometer should not be immersed in the liquid, but only 
introduced iuto the flask so far that the bulb may be enveloped by 




Fig. 70. 




Flasks arranged for finding the boiling-point of a liquid. 

the vapor of the boiling liquid, as shown in the illustrations. Heat 
should be carefully applied and gradually increased until the liquid 
boils actively, at which time the boiling-point will be indicated by 
the height of the mercurial column in the thermometer. Iu the case 
of very accurate determinations, it may be necessary to make correc- 
tions for increased or decreased atmospheric pressure, aud according 
to Kopp the correction amounts to 1° C. (1.8° F.) for every 27 milli- 
meters above or below the normal height of the barometer column of 
mercury. In order to avoid errors, which might arise from the cool- 
ing of the long mercurial column outside of the flask, specially con- 
structed thermometers, known as Zincke's thermometers (see page 90) 
are usually employed for temperatures above 100° C. (212° F.). 

Fusible substances, when gradually heated to their melting-point, 
do not all behave in the same manner; as a general rule, crystallizable 
bodies become brittle just before melting, while non-crystallizable 
substances assume a plastic condition. When fusion commences they 



84 GENERAL PHARMACY. 

combine, as it were, with heat in an intimate manner ; that is, they 
occlude heat, so that the further addition of heat does not cause any 
rise in temperature until all of the substance has become liquefied. 
The heat thus disappearing is called the latent heat of fluidity, because 
it is used to change the solid form of a body into the liquid form 
without any change in the temperature of the body ; thus if crushed 
ice be heated, the temperature will not vary from 0° C. (32° F.) while 
the ice is melting, and when completely changed to water, the tem- 
perature of the water will also be 0° C. (32° F.), provided the appli- 
cation of heat be not continued beyond fusion. The amount of heat 
necessary to produce complete fusion varies with different substances; 
thus in the case of ice it has been ascertained to be 79.25 C. or 
142.65 F. degrees ; this was determined as follows : Two vessels, con- 
taining respectively equal weights of ice and water at 0° C. (32° F.), 
and each provided with a thermometer, were heated in a bath of 
water ; at the moment when the ice had completely melted the tem- 
perature was indicated as still at 0° C. (32° F.), while the tempera- 
ture of the water in the other vessel had risen from 0° C. (32° F.) 
to 79.25° C. (142.65° F.). If a pound of ice at 0° C. (32° F.) and 
a pound of water at 100° C. (212° F.) be mixed so as to avoid loss 
by evaporation, the result, when all the ice has melted, will be two 
pounds of water at 10.4° C. (50.7° F.) ; whereas if a pound of water at 
0° C. (32° F.) be mixed with a pound of water at 100° C. (212° F.), 
the result would be two pounds at 50° C. (122° F.). In the first 
case, 79.25 C. (142.65 F.) degrees of heat were withdrawn from the 
boiling water to melt the ice at 0° C. (32° F.) into water at 0° C. 
(32° F.), but in the second case this was not necessary, and the mix- 
ture assumed the mean temperature of the two. The latent heat of 
fluidity of water being known as 79.25° C, a simple rule can be 
formulated for ascertaining the amount of ice necessary to reduce any 
given weight of water at stated temperature to a stated lower tem- 
perature, as follows : 

Add the desired temperature to 79.25° C. (142.65° I.) and divide 
the sum into the difference between the stated temperature of the water 
and the desired temperature — the quotient will be the required pro- 
portion of ice as compared with the given weight of water. 

Example : How much ice is required to cool 1000 Gm. of water 
from 100° C. to 25° C? 



79.25 100.0 
25.00 25.0 


104.25 ) 


75.000 (0.7194 

72975 


104.25 75.0 


20250 
10425 




98250 
93825 




44250 
41700 


:: 0.7194 of 1000, or 719.4 Gm. 





HEAT. 



85 



Proof: The ice needs 25° C, besides the 79.25° C. required for 

melting it, and the water loses 75° C. by being reduced to 25° C; as 

75 

the gain and loss must balance each other, it will require of 

1 104.25 

1000 Gm. of ice, or 791.4 Gm. 

The law regarding latent heat of fluidity has a practical bearing 
upon the fusion of various substances liable to be injured by expo- 
sure to a heat a little above their melting-points; thus, a pan of 
ointment or plaster may be kept over a direct fire, without fear of 
injury, as long a.s a portion of the contents remains unmelted, as the 
increased amount of heat is utilized in the change of the state of 
aggregation, therefore it cannot raise the temperature above that of 
the melting-point. 



Fig. 71. 



Fig. 72. 





Capillary tube and thermometer 
with tube attached. 



Ordinary method of finding the melting-point ot 
substances. 



The melting-points of solids are as variable as the boiling-points 
of liquids ; thus, while ice melts at 0° C. (32° F.) aud lard at 39° C. 
(102.2° F.), sulphur requires a temperature of 115° C. (239° F.) and 
pure morphine a temperature of 255° C. (491° F.) 



86 



GENERAL PHARMACY. 




The determination of the melting-point of a substance frequently 
leads to its identification, and is a most valuable adjunct iu the 
examination of its quality. Some little care is 
requisite in determining the melting-point so as 
to insure accurate results. The best plan is to 
put a little of the substance to be examined into 
a small capillary tube (Fig. 71), and, after cutting 
off the enlarged portion, which is only intended 
for convenience in filling, attach the tube to an 
accurate thermometer by means of a rubber band, 
in such a manner that the tube lies close against 
the thermometer and the substance is on a line 
with the bulb, as shown in Fig. 71. The ther- 
mometer thus arranged may be suspended in a 
beaker containing water, sulphuric acid, or par- 
affin, as shown in Fig. 72. The liquid is gradu- 
ally heated and the temperature accurately noted 
when the substance in the capillary tube melts. 

In order to insure greater uniformity in the 
heating of the mercurial column of the thermom- 
eter, a very excellent apparatus has been devised 
by Dr. Alfred Dohme, of this city, the construc- 
tion of which is very simple and is shown in Fig. 
73. Into the neck of a rounded glass cylinder 9 
inches long and 1 j- inches in diameter is fused a 
glass tube closed at one end and J inch in diam- 
eter. The thermometer, to which is attached the 
capillary tube containing the substance, is inserted 
into the inner tube by means of a perforated cork. 
Through the opening in the shoulder sulphuric 
acid is poured into the outer cylinder to the 
height of about 7J inches, and the apparatus hav- 
ing been supported by means of a burette clamp, 
heat is carefully applied, and the currents thus 
established in the acid communicate heat to the 
air in the inner tube, which is kept uniform by 
circulation of the fluid. As in the preceding 
experiment, the melting-point is noted by the 
height of the mercurial column when the sub- 
stance melts. 

The term temperature is used to designate inten- 
sity but not quantity of heat, which is measured 
by a thermometer, an instrument consisting of a 
narrow capillary tube of uniform bore, hermet- 
ically sealed at the upper end, and terminating 
below in a bulb of glass. The bulb and a por- 
tion of the tube are filled with mercury (in some cases with col- 
ored alcohol or toluene), and the whole is provided with a graduated 



Improved apparatus 
for the determination 
of melting-points. 



HEAT. 87 

scale for measuring the rise and fall of the liquid within the tube ; 
mercury is preferred for all temperatures not below — 40° C. (at 
which point it freezes), on account of its non-adhesion to the sides 
of the glass tube, and consequent convex surface, and its great 
sensitiveness to even the slightest change in temperature. Abso- 
lute alcohol, although admirably adapted to very low temperatures, 
cannot be used for measuring heat intensity above 78.3° C, its 
boiling-point. The space above the liquid in the tube is deprived 
of air, so as to insure the ready andjuniform rise of the liquid when 
expanded by heat. 

As all glass vessels continue to contract for some years after they 
have been made, absolutely correct measurement of temperatures can 
only be obtained if the error of the thermometer is known ; such 
error can easily be ascertained by two very simple experiments. 
Immerse the bulb of the thermometer in crushed ice for fifteen or 
twenty minutes, and note the point on the graduated scale to which 
the mercury will sink; after five minutes more of immersion, again 
examine to see whether the mercury has remained stationary; if the 
mercury receded to 0° C. (32° F.) and remained at this point, the 
thermometer is correct as far as the freezing-point is concerned. To 
test its accuracy at higher temperatures, suspend the thermometer in 
steam rising from pure boiling water, in such a manner that it is 
completely surrounded by it, for the unconfined vapor of a boiling 
liquid has the same temperature as the boiling liquid itself; after 
thirty minutes, note the point to which the mercury has risen and 
continue the heat for ten or fifteen minutes, and examine again; if 
the mercury has risen to 100° C. (212° F.) and remained at that 
point for ten or fifteen minutes, the thermometer may be considered 
correct as compared with the boiling-point of water. Cliuical ther- 
mometers, used by physicians for taking the temperature of fever 
patients, should be supplied with a certificate showing their error, as 
this in some cases may amount to nearly J degree. Since 1880 the 
Winchester Observatory at Yale College, New Haven, Conn., has had 
in operation a special bureau for the examination of thermometers ; as 
glass tubing will continue to contract for three or four years, clinical 
thermometers should have been "seasoned" for at least that time be- 
fore they are examined, so that any error found may remain constant. 

During the past two years, thermometers of great accuracy, in- 
tended for very high temperatures, up to 550° C. (1022° F.), have 
been made in Germany, of special glass, kuown as " Jena resistance 
glass," which is very hard and non-contractile. In order to pre- 
vent boiling of the mercury, which ordinarily occurs at about 
357° C. (674.6° F.), the capillary tube is expanded at the upper end 
and filled above the mercurial column with compressed dry carbon 
dioxide. Still more recently (1894) thermometers have been manu- 
factured in which the indicator consists of an alloy of sodium and 
potassium, instead of mercury, and which may be used for tempera- 
tures ruuning as high as 650° C. (1202° F.). The alloy is enclosed, 



88 GENERAL PHARMACY. 

as in the previous case, in " resistance " glass, and the space above 
the alloy is filled with nitrogen at such pressure that, when the bulb 
becomes red-hot, the pressure inside is equal to that of the atmos- 
phere. The glass of the bulb is attacked by the alloy and turned 
brown, but this occurs at the time of filling, aud the coating then 
formed upon the surface of the glass protects it from further action. 

For registering still higher temperatures, instruments known as 
pyrometers are employed, which are, however, not very trustworthy ; 
they are of two kinds, Wedgewood's pyrometer, based on the con- 
traction of clay, and Brogniart's pyrometer, based on the expansion of 
metals. When it is desirable to note the highest or lowest tempera- 
ture reached during any fixed time, maximum and minimum ther- 
mometers, so constructed that a small metallic or glass indicator is 
carried to the highest or lowest point reached by the mercury or 
alcohol, and left at that point when the volume again changes, are 
used. 

Three different thermometric registers, known as the Fahrenheit, 
Celsius or Centigrade, aud Reaumur scales, are in use. For scien- 
tific purposes the Centigrade scale is now universally employed, while 
the Fahrenheit scale is in common use in this country and Great 
Britain, and the Reaumur scale is ordinarily used in Continental 
Europe. The graduations of all three scales are arbitrary, yet based 
upon careful observations of the respective authors. Fahrenheit, a 
German, who invented the mercurial thermometer, in 1709, observed 
that a quantity of mercury immersed in a mixture of ice and salt 
(considered by him as the absolute zero of temperature) amounted to 
11,124 volume parts, and when immersed in melting ice expanded 
to 11,156 volume parts, showing an increase of 32; the same quan- 
tity of mercury immersed in boiling water expanded to 11,336 
volume parts, or an increase of 212. 

These observations led Fahrenheit to mark the freezing and boiling 
points of water at 32 and 212 degrees above zero respectively, and 
to divide the space between these two points into 180 equal parts. 
Reaumur, a Frenchman, found that 1000 volume parts of alcohol of 
a given strength increased to 1080 volume parts between the freezing 
and boiling points of water, and he marked these two extremes as 
and 80 respectively, dividing the intervening space into 80 equal 
parts. Celsius, a Swede, adopted the more convenient plan of cen- 
tesimal division, and fixed the freezing and boiling points of pure 
water at and 100 respectively ; his scale is generally termed the 
Centigrade scale and is preferred for scientific work. 

When writing temperatures on the different scales, it is customary 
to use the abbreviations F. or Fahr. for Fahrenheit, C., Cent, or Cels. 
for Celsius, and R. or R6aum. for Reaumur, as, 32° F., 100° C, and 
80° R. On all the scales, the degrees are divided into plus and minus 
degrees, as they may be above or below the zero point; the latter 
being always distinguished by the prefix of the — sign, and whenever 
this sign is wanting, the degrees of heat being understood to be above 



HEAT. 



89 



zero; thus 18° F. would indicate 18 degrees above 0, although 14 
degrees below the freeziug-point, etc. 

Fig. 74 illustrates the relative graduations on the respective 
therrnometric scales. 

As equal spaces on the Centigrade and Fahrenheit scales are divided 
into 100 and 180 degrees respectively, it follows that each degree on 
the former scale is equal to 1.8 degrees on the latter, and since 80 
degrees on the Reaumur scale equal 180 degrees on the Fahrenheit 
scale, every degree of the former must correspond to 2.25 degrees of 



R 



50 : 



Fig. 74. 
C 



Fig. 75. 



100' 



0° 



2IZ 



32' 



B.P 



FP 



In I II ( 1 1 
J ™ ™ 

Reaumur, Centigrade, and Fahrenheit 
thermometers. 



Section of Zincke's thermometer. 



the latter. Every Eeaumur degree is equal to 1.25 Centigrade degrees. 
The following: rules for the conversion of therrnometric values are 
useful. 

To convert Centigrade into Fahrenheit : Multiply by 1.8 and add 



90 GENERAL PHARMACY. 

32 ; for any number of degrees above or below the freezing-point on 
the Centigrade scale when multiplied by 1.8 yield the corresponding 
number of degrees above or below the freezing-point on the Fahren- 
heit scale. 

To convert Fahrenheit into Centigrade : Subtract 32 and divide by 
1.8 ; for any number of degrees above or below the freezing-point on 
the Fahrenheit scale when divided by 1.8 yield the corresponding 
number of degrees above or below the freezing-point on the Centi- 
grade scale. 

To convert Reaumur into Fahrenheit, or Fahrenheit into Reaumur, 
substitute 2.25 for 1.8 in the preceding rules. 

To convert Centigrade into Reaumur, divide by 1.25; and to con- 
vert Reaumur into Centigrade, multiply by 1.25. 

Examples : Convert 25° C. into F. ; 25 X 1.8 =45 and 45 + 32 
= 77. Answer, 77° F. 

Convert —15° C. into F. ; — 15 X 1.3 = —27 and —27 + 32 = 
5. Answer, 5° F. 

Convert —40° C. into F. ; —40 X 1.8 = —72 and —72 + 32 = 
—40. Answer, —40° F. 

Convert 60° F. into C. ; 60—32 = 28 and 28 -r- 1.8 = 15.55 + . 
Answer, 15.55 + ° C. 

Convert 18° F. into C. ; 18 —32= —14 and— 14-*- 1.8 = 
—7.77 + . Answer, —7.77 + ° C. 

Convert— 12.5° F. into C. ; —12.5 — 32= —44.5 and —44.5 
-*- 1.8 = _24.72 + . Answer, —24.72 + ° C. 

Convert 30° R. into F. ; 30 X 2.25 = 67.5 and 67.5 + 32 = 99.5. 
Answer, 99.5° F. 

Convert —5° R. into F. ; —5 X 2.25= —11.25 and —11.25 + 
32 = 20.75. Answer, 20.75° F. 

Convert 50° F. into R. ; 50—32=18 and 18-*- 2.25 = 8. 
Answer, 8° R. 

Convert 4° F. into R. ; 4 — 32=— 28 and —28^-2.25 = 
—12.4. Answer, —12.4° R. 

Convert 60° C. into R. ; 60 -*- 1.25 = 48. Answer, 48° R. 

Convert —8° C. into R. ; — 8 -*- 1.25 = —6.4. Answer, —6.4° R. 

Convert 28° R. into C. ; 28 X 1.25 = 35. Answer, 35° C. 

Convert —7.5° R. into C. ; —7.5 X 1.25= —9.37 + . Answer, 
— 9.37 + ° C. 

In order to avoid the use of the ordinary long thermometer for 
temperatures above 100° C, which might frequently prove annoying 
and give rise to inaccuracies in scientific work, special short ther- 
mometers have been devised, so constructed that the graduations of 
the scale begin a little below the boiling-point of water. (See Fig. 
75.) These instruments, known as Zincke's thermometers, are from 
4 to 6 inches in length, very accurately made, and are admirably 
adapted for testing the melting or boiling-point of substances at 
temperatures above 100° C. 



CHAPTEE V. 

COLLECTION AND PRESERVATION OF CRUDE DRUGS. 

Although the collection and preparation of vegetable drugs is 
not in the hands of the pharmacist, but is carried on, often in a small 
way, by special drug-gatherers and collectors, it is thought fit to 
refer to the subject here. 

The various parts of plants used in medicine cannot be gathered 
indifferently at all seasons of the year, since the peculiar juices of 
the plant in which its activity resides are more abundant in some 
parts than others at certain periods of the plant's growth. Roots of 
annual plants should be gathered immediately before the time of 
flowering; those of biennials, either late in the fall of the first year, 
or early in the spring of the second year, after the first appearance 
of the plant above ground ; perennial roots should not be gathered 
until after two or three years' growth, and, in some cases, even four 
or five years are allowed for full maturity. Fleshy roots must be 
sliced, either trausversely or longitudinally, previous to drying, in 
order to expose a larger surface to the air; whilst smaller and 
fibrous roots do not require this treatment. When artificial heat is 
to be used in drying roots, a temperature of 50° to 55° C. (about 
122° to 131° F.) will be found sufficient, except in the case of a few 
succulent roots, where the temperature may be raised to 65.5° C. 
(150° F.). 

Barks of trees should be gathered in the spring, but those of 
shrubs in the autumn, for at these seasons they are most readily 
separated from the wood. Only the inner bark being employed, the 
outer epidermis should be removed. 

Leaves begin to lose their activity after the flowers appear, for the 
juices of the plant then go toward nourishing the latter; they should 
therefore be collected when fully developed, before they begin to 
wither. Leaves of biennials must be collected during the second 
season. 

Herbs are generally understood to mean the whole plant, although 
the root is frequently rejected; they should be gathered when in 
flower. If the flowers are not to be used with the stem, the latter 
should be collected before the flowers appear, but after foliation. 

Flowers are preferably gathered before they are perfectly developed 
(expanded), since odor and color are then more pronouuced ; the red 
or French rose offers a striking example. They should be collected 
in the morning, after the dew has disappeared, and be dried, without 
artificial heat, in the shade. 



92 GENERAL PHARMACY. 

Fruits should be gathered before they are quite ripe ; but seeds, 
the least perishable of vegetable productions, must be perfectly ripe, 
and require very little drying. 

Crude vegetable drugs are rarely deprived of all their inherent 
moisture by the drug-gatherers, and invariably reabsorb moisture 
when exposed to a damp atmosphere ; before such drugs can be 
mechanically subdivided they frequently require a further drying by 
artificial heat, which is effected by spreading the material loosely on 
shelves in ventilated apartments heated by steam. While drugs 
containing volatile constituents, such as buchu, valerian, myrrh, 
spices, etc., demand a moderate heat, others again can be strongly 
heated until they become brittle, as, for instauce, squill ; a tempera- 
ture kept at or below 45° C. (113° F.) will not prove injurious in 
any case. 

The amount of moisture present in freshly gathered botanical 
drugs varies considerably, ranging from 15 or 20 per cent, in barks 
and wood to as much as 80 per cent, or more in some roots and 
leaves, and the object of thorough dryiug is partly to reduce the 
bulk, but chiefly to preserve the drug for future use ; for if vegetable 
drugs be packed away in a moist condition they soon begin to mould, 
or become heated, and undergo rapid deterioration. The loss in 
weight experienced by thorough drying of drugs is in many cases 
more than compensated for by the increase in value of the dried 
article, as in opium and other alkaloidal or resinous drugs. If 
opium containing 10 per cent, of morphine and 25 per cent, of 
moisture be dried perfectly, the loss in weight will amount to one- 
fourth, but the relative proportion of active principle is increased 
one-third • jalap tubers containing 8 per cent, of resin and 34 per 
cent, of moisture will lose upon drying about one-third of their 
weight, but the proportion of resin present is increased 50 per cent. 
Dried botanical drugs are best preserved in cool, dry rooms in con- 
tainers which shall exclude sunlight, but permit of free circulation 
of air ; odorous drugs should always be kept separate in order to 
avoid contamination of others ; for instance, a bale of buchu, vale- 
rian, or sassafras should never be stored by the side of senna leaves, 
elm bark, or flaxseed. 

As crude drugs reach the pharmacist they are frequently not in a 
condition to be offered for sale, or to be used in the preparation of 
medicines, on account of impurities present, and the process of gar- 
bling is a very necessary operation. The object of garbling, or pick- 
ing, is to remove, besides impurities and adulterations, decayed and 
deteriorated portions of the drug, which not only mar the appear- 
ance but are apt to contaminate the still healthy portion, and soon 
render the whole worthless. Senna leaves are generally accompanied 
by a considerable proportion of stems, broken capsules, and dust, 
not to speak of the fraudulent admixtures of stones, shells, etc., 
made by the gatherer or exporter for the purpose of increasing the 
weight; as much as 15 per cent, of impurities has been taken from 



COLLECTION AND PRESERVATION OF CRUDE DRUGS. 93 

what was bought as prime senna. Juniper berries are never free 
from unripe and decayed fruit, dirt and worm-eaten portions, which 
should be carefully removed. Fibrous roots, as spigelia, wild gin- 
ger, serpentaria, and the like, require to be freed from adhering dirt 
and other roots that grow side by side with them, and have become 
mixed through careless gathering. Although some drugs are found 
in much better condition than others, there are none which may not 
be improved in appearance, even if it be only to have the fine dust 
and dirt removed, as in the case of sassafras, wild cherry, crushed 
oak-bark, etc. ; lycopodium, fennel, flaxseed, and similar drugs, 
should be well shaken in a suitable sieve, to remove foreign matter, 
before putting them away in containers, and the careful pharmacist 
will find that this little extra labor is readily appreciated by his 
patrons, who are apt to judge a man largely by the appearance of his 
wares. Even vegetable powders, such as ipecacuanha, nutgall, aud 
others of similar character, must be passed through a fine sieve, pre- 
ferably bolting-cloth, to remove coarse particles which unfit them 
for dispensing purposes, and which have, in some instances, been 
found to amount to as much as 25 per cent, of the total weight of 
the powdered drug. 



CHAPTEE VI. 



MECHANICAL SUBDIVISION OF DBUGS. 



Fig. 76. 



Before employing vegetable drugs in the various pharmaceutical 
preparations it often becomes necessary to reduce them to a state of 
comminution, or of powder, more or less coarse or fine as the nature 
of the drug and the desired preparation may demand. By simple 
contusion is generally understood a rather coarse division, brought 

about by crushing or bruising in 
suitable apparatus preparatory to 
finer reduction ; for small operations 
an iron or brass mortar of bell or 
urn shape is employed, which should 
be deep and with a broad inner base, 
as shown in Fig. 76, the pestle being 
of such length and weight as will 
enable the operator to exercise con- 
siderable force if necessary. In 
contusing substances only such a 
quantity should be placed in the 
mortar at one time as to cover the 
bottom for the depth of an inch 
or two, and to avoid loss or un- 
pleasant results from the escape of 
dust or particles of drug, a cover, 
provided with a hole through which 
the pestle passes, should be used. In 
place of the mortar and pestle a cut- 
ting knife can frequently be used 
with advantage. The Champion Knife 
NTo. 2, Fig. 77, made by the Enter- 
prise Manufacturing Co., of Phila- 
delphia, is well adapted for the coarse 
division of roots, barks, and herbs, 
as it combines a drawing motion 
with pressure while cutting the material. When operating on large 
quantities, steam power is necessary, and the best apparatus for the 
purpose is that known as Mead's Disintegrator (see Figs. 78, 
79, and 80). The grinding is done in this mill by hardened 
steel beaters securely riveted on both sides of a steel disk. These 
beaters revolve on the feeding side of the mill between corrugated 
rings. The beaters catch the material as it enters the mill and beat 
it against the corrugates until it is fine enough to pass between the 




Sectional view of mortar and pestle 
for contusion. 



MECHANICAL SUBDIVISION OF DRUGS. 



95 



disk and the face of the ring ; as soon as it passes here it is on the 
discharge side of the mill, and all that is fine enough is immediately 




Cutter for herbs and roots. 




Fig. 




Front view. 



Mead's Disintegrator. 



Side view. 



driven out by the beaters on the back of 
the disk. What is not fine enough to dis- 
charge is caught by these back beaters and 
beaten against the screens until fine enough 
to pass through. The screens are made of 
square steel, and present a grinding sur- 
face to the beaters and a discharging sur- 
face between each bar ; they are two inches 
in width and extend around three-fourths 
of the diameter of the mill, thus giving a 
large discharging surface without diminish- 
ing the grinding surface. The material, as 
it is ground, falls into the box or room 
below. The most effective work is achieved 
with the disintegrator running at high 
speed, three thousand revolutions per min- 
ute ; under such conditions, six hundred 
pounds of wild cherry bark can be finely 
crushed in an hour. 

The production of very fine powders of 
drugs has long since passed into the hands 



Fig. . c o. 





a. Section of steel screen ; b. 
Section of corrugated ring ; c. 
Steel disk with beaters attached. 



96 



GENERAL PHARMACY. 



of the drug-miller, and even the coarser powders intended for 
percolation are to-day prepared by only a small number of phar- 
macists. For the latter purpose the drug mills shown in Figs. 
81 and 82 will be found very desirable In the New B Swift 
Mill the grinding is done between plates placed horizontally, while 
in the Enterprise Mill they are placed vertically. The grinding 
surfaces of both mills consist of circular chilled-iron castings 
studded with concentric rows of sharp teeth, those of one plate 
fitting between those of the other. The teeth decrease in size toward 



Fig. 81. 




The mill ready for use. 



New B Swift Mill. 



The mill open. 



the centre, and the fineness of powder is regulated by a pair of 
screws, by means of which the plates are made to approximate each 
other. One of the plates is stationary while the other revolves. 
Separate sets of plates for coarse and for very fine grinding can be had 
for the mills. Care should be taken to thoroughly clean the mill 
after each operation, else the remaining dust will surely contaminate 
the drug next ground. The simplest method of cleaning is to run 
sawdust through the mill repeatedly, then loosen the screws and 
remove the grinding plates, so as to wash these with hot water, if 
necessary, and dry quickly. A great mistake often made by the 
inexperienced is the attempt to produce fine powders at once by 
screwing the plates close together, instead of grinding the drug 
coarsely at first and gradually tightening the mill ; the first plan is 
apt to cause the material to become heated and cake, while the second 
plan will achieve the desired end more perfectly, with far less 



MECHANICAL SUBDIVISION OF DRUGS. 



97 



expenditure of manual labor and wear of machinery. Fig. 83 rep- 
resents the well-known Hance drag mill, having conical grinding 



Fig. 82. 




Enterprise drug mill (closed). 




Enterprise drug mill (open). 

plates, which possess the advantage over the usual styles of not 
allowing any material to pass through the mill unground (this some- 

7 



98 



GENERAL PHARMACY. 



times happens with vertical plates), and of not holding any of the 
ground material too long, whereby cloggiug may sometimes be caused 
with the horizontal plates. The mill is provided with an iron support, 
or may be had without it, to be mounted on a heavy block or box! 
For grinding small quantities at the dispensing counter the No. 450 



Fig. 83. 




Hance's drug mill. 

Enterprise Mill (Fig. 84) is admirably adapted ; it is constructed on 
the same principle as the larger Enterprise Mill shown before. All 
the before-mentioned hand-mills can be opened horizontally, as shown 
in the cuts, by means of a thumb-screw and hinge ; thus the interior 
may be readily exposed to view for examination or cleaning. The 
material is supplied through a capacious hopper, with its base 
specially arranged for crushing the drug into coarse particles. The 



MECHAXICAL SUBDIVISIOX OF DRUGS. 



99 



rapidity with which the material should be fed to the mill depends 
entirely upon the character of the drug, as some drugs will soften 
under the influence of heat and pressure, while others are not affected 
at all. Substances like vanilla, which cannot be heated before 
powdering, on account of the rapid loss of the aromatic principle, 
must be reduced in the soft condition; and, although the old method 



Fig. 84. 



Fig. 85. 





for vanilla. 

of grinding with sugar or clean 
sand is still largely in use, it is de- 
cidedly inferior to the process of 
cutting. Grinding or powdering 

vanilla has a tendency to press 
out the soft pulp, which soon re- 
tards the reduction of the tough 
fibre and requires the expenditure 
of much time and labor. If vanilla 
be reduced to the requisite degree 
of fineness for percolation by means 
of a rapid-acting cutter it retains practically its original condition, 
no pulp being expressed, and a powder is obtained far superior to 
that by grinding with sand or sugar. Fig. 85 represents the Ameri- 
can mince-meat chopper, an apparatus admirably adapted to the 
cutting of vanilla, and first suggested for this purpose, I believe, by 
Mr. X. H. Jennings, of this city. The large knife-blade with which 
the cutting is effected must be kept well sharpened. As the cylinder 
revolves with each turn of the lever, fresh particles of the material 
are continually presented to the knife, aud disintegration is rapidly 
achieved, while the aroma and virtue of the vanilla are kept 
intact. 

The grinding of drugs on a large scale, and particularly into very 
fine powder, is accomplished either in buhr-stone mills, iron mills, 
such as the Bogardus Eccentric Mill, or stone "chaser" mills. In the 
first- named mill, grinding is effected between two large stone disks 
placed horizontally and provided with numerous furrows to facili- 
tate the passage of the ground drug from the centre to the circum- 
ference ; one of the disks is stationary — in some mills the upper, and 



100 



GENERAL PHARMACY. 



Fig. 



iii others the lower — while the other revolves, the material being fed 
through an opening in the centre of the upper stone. By suitable 
approximation of the stone disks, powders of various degrees of 
fineness can be produced. 

The portable Bogardus Eccentric Mill (Fig. 8(3) is a great favorite 
with drug-millers, as it can be driven at a high rate of speed without 

becoming heated, and discharges the 
ground material promptly without 
danger of choking. Both grinding 
plates revolve in the same direction, 
on centres which are about one or 
two inches apart from each other, 
hence the name eccentric; this ar- 
rangement causes the material be- 
tween the plates to be moved about 
in every conceivable manner, to be 
acted upon by the plates at every 
point, and subjected to a peculiar 
twisting, cutting, and grinding motion, 
whereby it is rapidly disintegrated, 
with large results in quantity ground 
and the expenditure of but little 
power. In mills with single revolv- 
ing plates (the other being stationary), 
one plate continually describes the 
same circle on the other, so that mate- 
rial ground in these mills is subject to 
motion in one direction only, hence 
greater power and more time are 
necessary to accomplish the desired result than if the material were 
acted upon in various directions and by different motions. The rate 
of feeding the mill is controlled by an adjustable slide attached 
to the hopper, and the degree of fineness of powder is regulated by 
means of a screw and lever controlled by a weight. 

The so-called Chaser Mill is preferred when large quantities of 
material, such as cinnamon, ginger, pepper, mustard-seed, and the like, 
are to be reduced to impalpable powder. Fig. 87 shows a sectional 
view of a large chaser mill in use at the drug mills of Messrs. 
Gilpin, Langdon & Co., of this city. It consists of two large stone 
disks, or granite wheels, connected by a short metallic axle with a 
revolving shaft, which compels them to travel in fixed lines on a 
base of granite. The name chaser mill is derived from the motion of 
the disks — called chasers — which appear to chase each other in their 
travels over the stone base. The grinding of any material supplied 
to the mill is effected between the granite base and the outer edge of 
the chasers ; by means of iron scrapers appropriately fastened to the 
revolving shaft, the material is continually brought under the grind- 
ing edges again. As seen in the illustration, the base is surrounded 




Bogardus eccentric mill. 



MECHANICAL SUBDIVISION OF DRUGS. 



101 



by a curb, to prevent the coarsely-ground particles from mixing with 
the finer powder, which, by means of the draught created by the 
rapid revolution of the chasers, is carried upward and over the sides 
of the 'curb. The whole mill is enclosed in a dust-proof compart- 
ment, which is frequently provided with a series of shelves for the 
purpose of allowing the fine particles of powder to be deposited for 
subsequent convenient collection. The feeding of the mill is accom- 
plished through the top of the box, by means of a long funnel deliv- 
ering the material directly upon the stone base. 

Fig. 87. 




'fe.: ■:;;;--[ : r!P 



Chaser mill. 

Sifting. In order to produce powder ot uniform fineness, 
the ground substance should be subjected to the separating action 
of some perforated medium, whereby division into coarser and 
finer particles is readily effected. The construction of ordinary 
sieves is too well known to require special description. The perfor- 
ated material or netting used may be made of irou, brass, or tinned 
wire, hair-cloth for substances affected by metal, and silken cloth 
for very fine or dusted powders. Different degrees of fineness 
of powder are designated in the U. S. Pharmacopoeia by num- 
bers, which refer to the number of meshes to the linear inch in the 
material of which the sieve is made; thus, very fine or No. 80 
powder should pass through a sieve having 80 meshes to the linear 
inch (or 30 meshes to the centimeter) ; fine or No. 60 powder should 
pass through a sieve having 60 meshes to the linear inch (or 24 
meshes to the centimeter) ; moderately fine or No. 50 powder should 



102 



GENERAL PHARMACY. 



Fig. 88. 



pass through a sieve having 50 meshes to the linear inch (or 20 
meshes to the centimeter) ; moderately coarse or No. 40 powder should 
pass through a sieve having 40 meshes to the linear inch (or 16 
meshes to the centimeter); coarse or No. 20 powder should pass 
through a sieve having 20 meshes to the linear inch (or 8 meshes to 
the centimeter). While it is impossible to grind drugs entirely of the 
degree of fineness wanted for many purposes, the aim should be to 
keep the finer portion down to a low percentage by frequent sifting; 
as prescribed in the Pharmacopoeia, not more than one- fourth of the 
powder should pass through a sieve having 10 more meshes to the 
linear inch. It should also be borne in mind that some parts of 
the drug can be ground more readily than others ; it is therefore 
necessary to mix the powder thoroughly, after the grinding and sift- 
ing have been completed. The proper handling of a sieve cannot be 

definitely described, it must 
be taught practically; this 
much, however, can be said 
— that no effort should be 
made to force the material 
through the meshes of the 
sieve by persistent pressure 
of the hand, which will 
cause the meshes to open 
farther and allow coarser 
particles to pass through. 
In Fig. 88 is shown the well- 
known Harris Sifting Ma- 
chine, which some twenty- 
five years ago was exten- 
sively used by pharmacists ; 
readily understood. Of late 
in one piece of apparatus 




Harris' sifting machine. 



its construction is very simple and 
years, sifters and mixers combined 

have been greatly preferred ; such a combination, admirably adapted 
to the wants of the pharmacist who manufactures on a small scale, 
is shown in Fig. 89. Its capacity is 50 pounds, and the mixer 
is provided with a galvanized double spiral agitator so arranged 
that when the sifted powders come in contact with it the inside 
spiral carries the material one way, while the outside spiral carries it 
the other; thus a most thorough mixture is effected in a short time. 
After the powders have been mixed, the contents may be withdrawn 
by means of a slide in the bottom of the circular mixer. Smaller 
and larger sizes of the Lightning Sifter and Mixer are manufactured, 
and can be supplied with sieves of different degrees of fineness. 
Fig. 90 represents Jones' Mixer and Sifter, in which the mixing is 
effected on a different principle, by means of paddles and brushes ; 
its capacity is 10 pounds. These combined sifters and mixers are well 
adapted for the manufacture of Seidlitz mixture, tooth-powder, com- 
pound liquorice powder, etc., without the annoyance of dirt and dust. 



MECHANICAL SUBDIVISION OF DRUGS. 



103 



Powdered drugs are frequently offered at prices lower than those 
asked for a good quality of the crude drug ; yet it is well known that 



Fig. 89. 



Fig. 90. 





Jones' mixer and sifter. 

the cost is enhanced by loss in 
drying, expense of powdering 
(from 3 to 10 cents per pound), 
and other incidentals. There can 
be but one explanation for this 
anomaly : either an inferior quality 
of drug has been ground, or ad- 
mixtures have been made to in- 
crease the yield of the powder. As detection of the fraud is not 
within the reach of all, powdered drugs should be purchased only 
from dealers whose sense of truth and honor is paramount to their 
cupidity. Owing to the largely increased surface exposed to light 
and air in the case of powdered drugs, they are, as a rule, more 
liable to deterioration than crude drugs, and should therefore be 
more carefully protected, particularly against moisture. 

Among other methods for the mechanical subdivision of drugs may 
be mentioned trituration, which consists in reduction of a substance to 
very fine powder by continued attrition of the particles between the 
hard surface of a pestle and the sides and bottom of a mortar. Tritura- 
tion is usually applied to saline aud similar chemical substances, and 
the mortars best adapted to the process are those made of Wedgewood 
ware, of the shape shown in Fig. 91. A rotary motion of the pestle 
accompanied by pressure is productive of the best results in tritura- 
tion, the circles described being gradually enlarged from the centre 
outward and back again to the centre. A thin layer of the material 
should be kept between the pestle and the sides of the mortar. When 
the powder begins to cake and fall toward the centre of the mortar, a 
spatula should be run around the sides so as to loosen up and mix 
the different portions. The term trituration is also sometimes em- 
ployed to designate the thorough mixture of vegetable or other 



104 GENERAL PHARMACY. 

powders by rubbing them well together in a mortar ; in such cases 
little if any pressure is employed, and thorough blending of the 
mixture is facilitated by frequently scraping the powder down from 
both pestle and mortar with a spatula. 

The reduction of substances to fine powder by triturating them in 
the presence of a liquid having no solvent effect upon them, is termed 
levigation. The process is usually conducted in broad, shallow mor- 
tars. Formerly, when a stone slab and muller were employed, this 
method was also known as porphyrizatiou, from porphyry, a very 
hard stone, the material of which the slab was made. Water, alcohol, 

Fig. 91. 




Wedgewood mortar and pestle. 

or oil may be used as suitable media for levigation, the process con- 
sisting of the formation of a soft paste of the substance to be pow- 
dered and the liquid, this paste being then triturated or ground until 
perfectly smooth. Red mercuric oxide may thus be reduced to an 
impalpable powder by trituration with alcohol, and white paints, such 
as zinc oxide and lead carbonate, are ground smooth with oil in 
special paint mills. 

Elutriation is a process intended for obtaining certain inorgauic 
substances in a finely pulverulent condition, by diffusing them in 
water after they have been ground or crushed ; the coarser particles 
then rapidly subside, owing to their higher specific gravity, while the 
water holding the fine powder in suspension is decanted and allowed 
to settle in another vessel, the decautation being repeated a second 
time if necessary. To facilitate drying of the elutriated powder, 
the magma or soft mass is drained as completely as possible, and then 
formed into small conical nodules, which are conveniently dried on 
warm porous tiles. The well-known soft prepared chalk, French 
bismuth subnitrate, and numerous lake colors, are obtained as fine 
powders by elutriation. 

Other methods for the mechanical subdivision of drugs are pre- 
cipitation, reduction and granulation. 



MECHANICAL SUBDIVISION OF DRUGS. 105 

By precipitation is understood the sudden destruction of the 
soluble form of a substauce which is held in solution ; this may be 
effected by the addition of another substance to the solution, or by 
some external agency. The substance thus thrown out of solution is 
termed the precipitate, and the substance or force causing the separa- 
tion, the precipitant. Precipitation is employed in pharmacy as a 
method of pulverization and purification, and as a convenient means 
for obtaining many insoluble substances. 

The first of these comes under the head of what may be termed 
simple or physical precipitation, usually brought about by the addi- 
tion to the solution of some substance in which the dissolved body 
is insoluble ; as in the precipitation of ferrous sulphate or of tartar 
emetic from aqueous solution by means of alcohol. Other examples 
of physical precipitation are the separation of iodine or camphor 
from alcoholic solution by the addition of water, the precipitation of 
solution of acacia by alcohol, the precipitation of lime-water by 
boiling, and the preparation of the official resin of jalap. 

The process of precipitation when intended as a means of purifica- 
tion, or of the preparation of insoluble compounds, almost invariably 
involves chemical action, as in the purification of metals by electro- 
lysis, the manufacture of mercuric iodide, etc.; in the former case 
simple decomposition of a salt is effected, while in the latter case 
mutual decomposition between two salts is as a rule necessary. 

Some insoluble compounds are precipitated by simple decomposi- 
tion of a substance by meaus of water, as bismuth subnitrate, yellow 
mercuric subsulphate, etc. ; in the former case an acid solution is 
freely diluted with water, in the latter case white mercuric sulphate 
is thrown into boiling water. 

Mercuric oxide can be obtained in a much finer state of division 
by precipitation than by any other method, but it must be brought 
about by chemical action. If a solution of mercuric chloride be 
poured into a solution of sodium or potassium hydroxide two new 
compounds, yellow mercuric oxide and sodium chloride, are formed, 
the latter remaining in solution, while the former separates as an 
impalpable powder, being insoluble in all neutral liquids. Lead 
iodide, magnesium carbonate, ammoniated mercury, and precipitated 
chalk are familiar examples of compounds prepared by chemical 
precipitation. 

The character of the precipitate depends largely upon the condi- 
tions under which its formation is effected ; thus, concentrated solu- 
tions are apt to yield dense precipitates, particularly if heat be 
employed, whereas cold dilute solutions, as a rule, produce light 
bulky precipitates. In the preparation of new chemical compounds 
by precipitation it is important that the proportion in which the 
precipitant is to be employed should be determined by calculation, 
as a deficiency or au excess may result in loss from imperfect pre- 
cipitation or re-solution of the precipitate. Mutual decomposition 
between two salts always takes place in definite molecular propor- 



106 GENERAL PHARMACY. 

tions, and the necessary quantities may be readily ascertained by 
writing out an equation showing the decomposition ; thus the forma- 
tion of yellow mercuric oxide is demonstrated by the equation 
HgCl 2 + 2NaOH = HgO + 2NaCl + H 2 0, which shows that 1 
molecule or 270.54 parts of mercuric chloride requires 2 molecules 
or 79.92 parts of sodium hydroxide for complete precipitation. In 
this case an excess of sodium hydroxide is not hurtful, but a 
deficiency would result in the production of mercuric oxychloride 
of brownish color instead of a pure yellow oxide. The equation 
HgCl 2 + 2KI = Hgl 2 + 2KC1 shows that in the formation of red 
mercuric iodide 2 molecules or 331.12 parts of potassium iodide are 
necessary for the complete precipitation of 1 molecule or 270.54 
parts of mercuric chloride ; these proportions must be strictly ob- 
served, otherwise a loss will result, as red mercuric iodide is soluble 
in both potassium iodide and mercuric chloride solutions. When 
precipitation by mutual decomposition between two salts is proposed, 
the salts are mixed in the form of separate solutions, and perfect 
blending is accomplished by stirring the mixture. 

The most convenient style of vessel for precipitation is a glass or 
stoneware jar considerably broader at the base than at the top, and 
provided with a lip; this greatly facilitates the subsidence of the pre- 
cipitate, and the subsequent removal of the clear liquid remaining 
above the precipitate, known as supernatant liquid. 

The purification of precipitates is effected by a process of washing, 
which consists either in mixing them repeatedly with fresh portions 
of water in a suitable jar, and decanting the supernatant liquid after 
it has become perfectly clear, or in continued affusions of water on 
the precipitate contained in a cloth strainer or paper filter ; each 
portion of water should be well mixed with the precipitate and the 
washing continued until the complete removal of the soluble by- 
product has been ascertained by appropriate tests. When a precipi- 
tate tenaciously retains liquid, forming a thin paste, the mixture is 
termed a magma, and forcible expression must frequently be resorted 
to in order to remove the liquid, as in the case of washing ferric 
hydroxide, freshly precipitated calcium j)hosphate, etc. 

The official reduced iron is an instance of a metal obtained in a 
finely divided state by reduction; ferric oxide being heated to redness 
in an atmosphere of hydrogen, in suitable tubes, and allowed to cool 
without contact of air. This method of producing metallic iron in 
fine powder yields better results than any other known. 

Granulation is a process by which certain substances soluble in 
water are obtained in the form of coarse powder by simple evapora- 
tion of their solution, with constant stirring, until all moisture is 
dissipated. It is employed either for deliquescent and difficultly 
cry stall izable substances, as potassium citrate and carbonate, or in 
cases where the solution, if allowed to evaporate very slowly, would 
yield larger crystalline masses, as ammonium chloride, lead acetate 
etc. Granulated powders, as the name indicates, never represent a 



MKCJL 1 NIC 'AL SUBDIVISION OF BR UGS. 107 

fine state of division, but offer a very convenient form for dispensing 
purposes. Zinc and tin may be readily granulated in the metallic 
state by heating them to a temperature a little below their melting- 
poiut, when they become very brittle, and can then be rubbed into 
coarse powder in a mortar. 

Some substances obstinately resist pulverization by any of the 
methods mentioned, and require a different treatment; for instance, 
camphor cannot be reduced to a fine powder without being first 
brought to a state of partial or perfect solution by means of alcohol; 
a smooth paste being first formed of camphor and alcohol in a mortar, 
which is then triturated until perfectly dry and in the form of an im- 
palpable powder — excessive pressure should be avoided during the 
trituration. Powdered camphor thus prepared is apt to return 
gradually to a crystalline condition, no matter how carefully it is pre- 
served, but this can be prevented by precipitating the camphor in the 
presence of some powder with which it will become intimately mixed. 
Such a process was first published in Parrish's Treatise on Pharmacy, 
and is as follows: Four ounces of camphor dissolved in 8 fluidounces 
of alcohol are poured slowly, with constant stirring, into a smooth 
mixture of 15 grains of calcined magnesia and 2 pints of water ; the 
precipitated camphor, enveloping the magnesia, soon rises to the sur- 
face, and is recovered by pouring the whole mixture on a paper filter, 
where it is allowed to drain. To facilitate drying of the mass, it is 
cut with a spatula into small particles, and is finally preserved in 
bottles. Although retaining a very small amount of moisture, this 
precipitated camphor keeps excellently, and may be used for all pur- 
poses requiring camphor, except cases of solution. Iodoform and 
boric acid can also be quickly reduced to an impalpable powder 
by trituration with alcohol, whereby partial solution is effected, and a 
dry powder is obtained upon evaporation of the alcohol. Friable 
substances, which are not held together by strong cohesive force, but 
the particles of which are apt to cake when submitted to pressure, 
may be powdered by simple friction over a perforated surface ; no 
better method is known for obtaining magnesium carbonate in an 
impalpable condition than by rubbing the cakes over the surface of 
an inverted bolting-cloth sieve. 



CHAPTEE VII. 

SOLUTION. 

When a solid body is brought into contact with a fluid in such an 
intimate manner that it loses its original form and assumes that of 
the fluid, producing a clear and uniform liquid, the process is termed 
solution, as is also the newly- formed homogeneous liquid ; but solution 
is by no means restricted to the liquefaction of solids by fluids, as 
gaseous and liquid substances can also be brought to the condition of 
perfect molecular blending characteristic of solution. The fluid used 
to produce solution is called a solvent or menstruum. The hypotheses 
at present engaging the minds of scientists regarding the electro- 
chemical decomposition of bodies in a state of solution need not be 
considered here; by some the process of solution is looked upon as 
one of great force and activity, and this view may in the course of 
time clear up many hitherto unexplained phenomena. 

Two kinds of solution are recognized, namely, simple and complex 
solution ; in the former the solvent produces no change in the sensi- 
ble characteristics of the dissolved body, simply altering its physical 
condition, while in the latter, where solution takes place as the result 
of chemical action, the properties of both the solvent and the dis- 
solved body become modified by the loss of old or the acquisition of 
new properties. In the case of a simple solution, the taste, odor, 
color, and chemical properties of the dissolved body remain intact 
and are imparted to the solution ; as, for instance, solutions of sugar, 
table-salt, or potassium permanganate in water. In simple solutions 
the dissolved body can be recovered in its original condition by evap- 
oration of the solvent. Complex solutions should not be confounded 
with compound solutions ; the latter term indicates a mixture of solu- 
tions, which may all be simple in character, while complex solutions 
are understood to be the result of chemical action and are accompanied 
by one or more of the following phenomena: heat, effervescence, 
change of color, odor, and taste; as, for example, the solution of a 
Seidlitz powder or the solution of red mercuric oxide in nitric acid. 
The products obtained by evaporation of a complex solution will be 
found to have new properties, not possessed originally by the solvent 
or the dissolved body. 

The greater the extent of surface exposed by the solid body to 
the liquefying action of the solvent, the more rapidly will solution 
be effected ; hence mechanical division facilitates solution, because the 
latter process is in direct opposition to cohesion. A simple solution 
of solid substances may be considered as a fluid produced by the 



SOLUTION. 109 

intimate union of the solvent and the dissolved body in a state of 
minute division, the union and division being so complete that the 
forces of cohesion and gravity are suspended, otherwise a mixture 
only is produced, and the solid substance will again separate. The 
agitation of a mixture of a solid substance and solvent also causes 
more rapid solution, by constantly bringing fresh portions of the 
fluid into contact with the solid ; if equal weights of acacia or 
sugar, in lumps or in fine powder, be placed in separate vessels 
with a sufficient quantity of water, the one being actively stirred 
while the other is allowed to remain at rest, solution will be com- 
pleted in the former vessel long before it occurs in the latter ; this is 
due to the fact that in the second vessel a dense solution will form 
immediately around the solid particles, and thus prevent the re- 
mainder of the fluid from exerting its solvent action. 

The term " solubility," when no solvent is mentioned, always refers 
to the behavior of the substance toward water at the ordinary 
temperature, about 15.6° C. (60° F.) ; thus the statements that 
sugar is soluble and bismuth subnitrate is insoluble refer solely to 
the liquefying effect which water will have upon the two substances. 
Different degrees of solubility are expressed by such terms as 
sparingly soluble, soluble, and very soluble ; these varying degrees of 
solubility do not determine the rapidity of solution, for some sub- 
stances are known to dissolve slowly but to a greater extent than 
others which enter into solution more rapidly but in less proportion. 
Substances differ greatly in their solubility in water ; as extremes 
may be mentioned zinc chloride, soluble in one-third of its weight of 
water, and barium sulphate, which requires about eight hundred 
thousand times its weight of water for solution. Substances but 
slightly soluble in water may be very soluble in other liquids; as 
camphor, which requires about 1000 parts of water for solution but 
is readily soluble in one-third of its weight of chloroform. 

Heat, as a rule, favors the solution of solids and diminishes the 
solubility of gases, but there are no substances totally insoluble in 
the cold which become soluble by the aid of increased temperature. 
The effect of the application of heat is the establishment of currents 
in the liquid which will facilitate solution just as agitation of the 
vessel favors the same result; and moreover, since heat intensifies 
molecular motion in both the menstruum and the solid, not only will 
an increased quantity of the latter assume the fluid state, but solution 
will also be effected in less time, on account of the energetic intra- 
molecular activity. There are some exceptions to the general rule 
that heat increases the solubility of substances; for instance, common 
salt is about as soluble at ordinary temperatures as at the boiling- 
point of water; sodium sulphate or Glauber's salt increases in solu- 
bility rapidly from 15° C (59° F.) to 34° C. (93.2° F.), at which point 
water takes up four times its weight of the salt, but beyond this tem- 
perature its solubility again decreases until 100° C. (212° F.) is 
reached, when water takes up about 2.13 times its weight of the salt ; 



HO GENERAL PHARMACY. 

calcium citrate and sulphate as well as slaked lime are far less soluble 
in hot water than in cold, and will be readily deposited if their 
solutions be boiled. 

The Pharmacopoeia, in the case of nearly every soluble substance, 
indicates the degree of solubility by stating the number of parts by 
weight of the solvent necessary to dissolve one part of the substance ; 
this proportion is usually given for both normal and boiling temper- 
atures. The pharmacist must be familiar with the methods for 
determining the solubility of substances, so as to be able to apply 
the official tests intelligently. At ordinary temperature, 15° C. 
(59° F.), a simple but accurate plan is to place some of the sub- 
stance in fine powder in a wide test-tube, or small flask, provided 
with a stopper, and add as much of the solvent as may be necessary, 
leaving, however, a small portion of the substance undissolved — 
shake the flask freely, or stir the contents of the tube briskly with a 
glass rod, warm the mixture slightly in a water-bath and allow it 
to cool down to 15° C. (59° F.), by placing the tube or flask in 
water having that temperature. In order to avoid a supersaturated 
solution, the mixture should next be set aside for twenty-four hours 
at normal temperature, and occasionally stirred with a glass rod, 
the sides of the tube or flask being also rubbed with the rod. 
The solution thus obtained is passed through a small dry filter into 
a tared glass or porcelain dish, and weighed ; after evaporation to 
dryness, the residue is carefully weighed, when the difference be- 
tween the weight of the solution and that of the dry residue repre- 
sents the weight of solvent, and from this the ratio of solubility is 
easily calculated. Example: Suppose the clear filtrate weighs 10.5 
Gm. (or 162 grains) and the dry residue therefrom 1.125 Gm. (or 
17.36 grains), then the weight of the solvent must be 9.375 Gm. 
(or 144.64 grains), and the substance under examination is soluble in 
8.33+ parts of the liquid used, for 9.375-- 1.125 or 144.64-- 
17.36=8.33 + . 

The determination of the solubility of a substance at temperatures 
above the normal becomes more difficult on account of the loss 
incurred during the filtration of hot liquids by ordinary methods. 
Dr. Charles Rice has devised a very useful and simple apparatus, 
called by him a lysimeter (from the Greek A&wf, solution), which 
enables the operator to obtain a clear filtrate without any loss what- 
ever, even at the boiling temperature of liquids. Fig. 92 shows 
the construction of the lysimeter, which consists of a glass tube, 
a, 15 centimeters (6 inches) in length and 1 centimeter (§• inch) in 
external diameter, provided at one end with a well-ground stopper, 
c, while the other end is cup-shaped, there being a contracted neck 
between the cup aud the main tube. Into this cup is made to fit a 
carefully ground glass bell, e, having a small perforation in its 
bottom, as shown in /; there is also a stopper, b, which is carefully 
ground to fit into the cup, and which is inserted after the glass bell, <?, 
has been removed. 



SOLUTION. 



Ill 



Fig. 92. 




^s 






When using the apparatus it is necessary to provide sufficient 
liquid to allow at least one-half of the tube, a, to be immersed : 
beaker glasses, or preferably wide test-tubes, may be used for effect- 
ing the solution. Suppose it is desired to ascertain the solubility of 
a substance in boiling alcohol. The following 
is the plan of procedure : Insert the stopper, 
c, into the tube, a, and into the cup-shaped 
end insert the glass bell, c, containing a pledget 
of purified cotton, and secured in place by a 
thin platinum wire passing around the con- 
tracted neck and over the mouth of the bell. 
Sufficient alcohol having been put into a wide 
test-tube or a beaker, the same is heated in a 
water-bath and the finely-powdered substance 
added until, after boiling has continued for 
sometime, a portion of the substance remains 
undissolved. The ly si meter, prepared as 
above directed, is now inserted into the liquid, 
and when the tube has assumed the tempera- 
ture of the boiling liquid the stopper, c, is 
removed, which allows the solution to filter 
through the pledget of cotton and rise in the 
tube as far as the quantity of fluid will per- 
mit. If the filtered solution be allowed to flow 
back through the cotton once or twice, greater 
uniformity of the liquid will be insured. The 
stopper, c, is now reinserted, the apparatus 
withdrawn from the liquid and turned upside 
down to allow the bell, e, to be removed and 
the stopper, b, to be inserted in its place. The 
stoppered tube is carefully cleaned externally 
by washing with alcohol, and laid aside until 
cold. The tare of the stoppered tube having 
previously been ascertained, the increase in 
weight must represent the weight of the solu- 
tion contained therein. After transferring the 
solution to a tared capsule or beaker, the tube 
is carefully rinsed with alcohol, and the wash- 
ings added to the contents of the capsule or 
beaker ; the solution is slowly evaporated on 
a water-bath, and afterward heated to dryness 
in a drying oven, when the weight of the 
residue will indicate the weight of the dis- 
solved substance, and subtracting this from the weight of the solution 
gives the weight of alcohol. From these data the ratio of solubilitv 
is calculated in the manner already explained in the example given 
for determining the solubility at normal temperature. 

Rapid simple solution of solid bodies is always accompanied by a 




Dr. Rice's lvsimeter. 



112 GENERAL PHARMACY. 

fall in temperature, while a solution of gases causes a rise in tempera- 
ture ; these phenomena are in accordance with the laws governing the 
state of aggregation of bodies. Solids, for the assumption of the 
fluid state, require a certain amount of heat, which is withdrawn from 
the surrounding liquid and becomes latent, while gases when con- 
densing to liquids give out au amount of heat corresponding to that 
required for the gaseous state. Four ounces of ammonium nitrate or 
potassium iodide rapidly shaken in a bottle with two ouuces of pure 
water will produce sufficient cold to coudense the moisture of the air 
ou the outside of the bottle and freeze it into thin sheets of ice. 

Saturated Solutions, in a pharmaceutical sense, are such as can- 
not take up any more of the dissolved body at ordinary temperature, 
in other words, the solvent has become charged with as much soluble 
matter as it is capable of retaining in intimate uuion at the ordinary 
temperature. The statements of ratio of solubility in the Pharma- 
copoeia and elsewhere always refer to the formation of saturated solu- 
tions at the temperature named ; thus the official statement that cane 
sugar is soluble at 15° C. (59° F.) in J part of water and 175 parts 
of alcohol, in -J- part of boiling water and 28 parts of boiling alcohol, 
means that, with the proportions of water, and alcohol named, sugar 
forms saturated solutions at the temperatures indicated. Super- 
saturated solutions are those in which the solvent, by artificial 
means, has been made to take up more of the soluble matter than 
it is capable of retaining under ordinary circumstances ; they are 
very unstable and present a peculiar condition of solubility. If 
three parts of sodium sulphate be dissolved in one part of water 
at 30° C. (86° F.), the solution carefully filtered into a perfectly 
clean dry bottle free from dust, and allowed to cool down gradu- 
ally, it will remain clear as long as it is not disturbed, although 
supersaturated, since water at 15° C. (59° F.)can dissolve only about 
one-third of its weight of the salt; but, if the bottle containing the 
supersaturated solution be shaken, or a little broken glass be intro- 
duced, the whole contents will suddenly congeal to a crystalline mass. 
Saturated solutions of salts are frequently capable of dissolving other 
salts, and thus may be used for purposes of purification ; if potassium 
nitrate be treated with a saturated aqueous solution of the same salt 
no more potassium nitrate can be taken up, but impurities present 
will enter into solution and are thus removed. 

The effect which the presence of one substance may have upon the 
solubility of another is interesting as well as of practical value in 
pharmacy; frequently the increased solubility thus produced is due 
to a chemical reaction between the two substances. Thus corrosive 
sublimate is far more soluble in water in the presence of alkali 
chlorides, and red mercuric iodide is readily dissolved in a solution 
of potassium iodide ; in both cases union takes place between the 
mercuric and alkali salts. The increased solubility of potassium 
chlorate in the presence of sodium bicarbonate is well known ; 
mutual decomposition, no doubt, results — the newly formed salts, 



SOLUTION. 113 

sodium chlorate and potassium bicarbonate, requiring only 1.1 part 
and 3.2 parts of water at 15° C. (59° F.) respectively for solution, 
as against 16.7 and 11.3 parts for the original salts. Ordinarily 
iodine requires about 5000 parts of water for solution, but if mixed 
with twice its weight of potassium iodide, will readily dissolve in 
20 times its weight of water. In this case no chemical union takes 
place, as the iodine has every appearance of being dissolved but not 
combined ; it retains its characteristic color and odor, and if the solu- 
tion be heated in a test tube, the iodine can be completely volatilized, 
a portion resubliming in the cooler part of the tube in its original 
condition. 

Since rapid simple solution causes a decided fall in temperature, 
advantage is taken of the fact that some substances hasten the lique- 
faction of others in the production of so-called freezing-mixtures ; 
thus, 5 parts each of ammonium chloride aud potassium nitrate dis- 
solved in 19 parts of water will cause a drop in temperature of 20° 
C. (36° F.) ; a mixture of 2 parts of snow and 3 parts of crystallized 
calcium chloride will cause the temperature to fall from 0° C. (32° 
F.) to — 45.5° C. ( — 50° F.) aud freeze mercury ; the usual mix- 
ture for ice-cream freezers consists of salt with twice its weight of 
snow or crushed ice, which produces a temperature equal to about 
— 20° C. ( — 4° F.), the cream in the cylinder freezing by reason of 
the great abstraction of heat necessary for the rapid liquefaction of 
the ice and snow surrounding it — not, as some persons imagine, 
because intense cold is imparted to it from the outside. 

Anhydrous salts, that is, salts completely deprived of water, will 
frequently cause a rise in temperature when brought into solution ; 
the heat thus generated must be looked upon as due to chemical 
action caused by the water in restoring the anhydrous salt to the 
crystallized state. If crystallized sodium carbonate be shaken with 
twice its weight of water a marked fall in temperature will be 
noticed, whereas anhydrous sodium carbonate shaken with twice its 
weight of water causes a rise in temperature, thus proving 
the correctness of the preceding supposition. When liquids are dis- 
solved in other liquids, no change of temperature will occur in the 
mixture unless contraction of volume takes place, as in the case of 
alcohol and water or sulphuric acid and water. 

The simplest way of effecting solution of solids is to bring them 
in the form of powder into contact with the solvent in such a way 
that frequent agitatiou of the mixture is possible ; for saline and 
similar substances a porcelain or Wedgewood mortar, which admits 
of active trituration, is best adapted. Considerable saving of time 
may be effected in the solution of larger quantities of solids, if the 
powdered substance be repeatedly triturated with fresh portions of 
the solvent, each portion of solution being poured off when saturated. 
Small quantities of readily soluble substances, such as potassium 
iodide and bromide, silver nitrate, zinc sulphate aud the like, may be 
placed directly in a bottle with the solvent, and the mixture agitated 



114 GENERAL PHARMACY. 

until perfect solution results. Some substances, of hygroscopic or de- 
liquescent character, are preferably not reduced to powder before add- 
ing the solvent, in order to avoid agglutination ; such are the official 
scale salts of iron, which will dissolve more speedily if shaken with 
water in scale form than in fine powder. Whenever heat must be 
employed for small operations of solution, a glass flask will be found 
more desirable than a dish, as evaporation of the solvent will be 
retarded, and consequently the heat become concentrated in the 
vessel. Solutions of solids are known to be denser than the solvents 
used in preparing them, and advantage is frequently taken of this 
fact to facilitate the solution of large quantities of solid substances, 
or of such as are liable to form viscid solutions, or where stirring or 
agitation is impracticable, by what is commonly known as circulatory 
displacement, which consists in suspending the soluble matter just 
below the surface of the solvent, either on a porous diaphragm, in 
a bag of loosely textured cloth, or in a perforated vessel, which should 
be moved about irom time to time. By this arrangement, that por- 
tion of the solvent least charged with soluble matter is always in 
contact with the solid, and as the solution becomes saturated it sinks 
to the bottom, displacing the portion less charged with the solid, 
which rises to the surface, and thus a continual circulation or system 
of currents, favorable to rapid solution, is kept up in the fluid. 

Percentage Solutions. This term is applied to solutions of 
definite strength, containing a specified amount of soluble matter 
in one hundred parts of the solution : for solids and gases percentage 
solutions should always be prepared by weight, while for liquid 
substances either w T eight or volume may be employed. The quantity 
of soluble substance and solvent necessary to make a specified quan- 
tity of any particular percentage solution may be readily ascertained 
by the following rule: Multiply the quantity of solution desired, in 
grammes or grains, by the number expressing the percentage, divide the 
product by 100, and the quotient will indicate the quantity of soluble sub- 
stance necessary ; subtract this from the total quantity of solution desired, 
and the remainder will indicate the necessary quantity of solvent. 

Examples : Wanted 500 Gm. of 10 per cent, carbolized oil : 500 
X 10 = 5000 and 5000 -r- 100 = 50 ; 500 — 50 = 450. Answer : 
Dissolve 50 Gm. of crystallized carbolic acid in 450 Gm. of olive oil. 

W 7 anted 750 grains of 4 per cent, cocaine hydrochloride solution ; 
750 X 4 =3000 and 3000 -r- 100 = 30; 750 — 30 = 720. Answer: 
Dissolve 30 grains of cocaine hydrochloride in 720 grains of distilled 
water. 

Wanted 640 Gm. of 2 per cent, mercuric chloride solution : 640 
X 2 = 1280 and 1280 -*- 100 = 12.8 ; 640 — 12.8 = 627.2. 
Answer : 12.8 Gm. of mercuric chloride must be dissolved in 627.2 
Gm. of distilled water. 

Wanted 480 grains of 20 per cent, quinine oleate : 480 X 20 ■ = 
9600 and 9600 -^ 100 = 96 ; 480 — 96 = 384. Answer : Dissolve 
96 grains of quinine alkaloid in 384 grains of oleic acid. 



SOLUTION. 115 

Sometimes a percentage solution of two or three substances is 
wanted ; in such a case the absolute quantity of each active ingre- 
dient is first ascertained by the rule given above ; the sum of their 
weights is then subtracted from the total quantity of solution desired 
to find the necessary weight of the solvent ; for instance : Wanted 
240 grains of 8 per cent, cocaine hydrochloride solution, containing 
also 2 per cent, of boric acid : 240 X 8 = 1920 and 1920 -f- 100 = 
19.2 ; 240 X 2 = 480 and 480 -*. 100 = 4.8 ; 19.2 '+ 4.8 = 24 ; 
240 — 24 = 216. Answer: Dissolve 19.2 grains of cocaine hy- 
drochloride and 4.8 grains of boric acid in 216 grains of distilled 
water. 

When a definite volume of a weight percentage solution is wanted, 
the quantity nearest in volume to that required must be made; 
although this sometimes involves a slight loss, there is no other 
method known if accuracy is to be preserved. Thus, if 2 fluidrachms 
of a 4 per cent, solution of any soluble chemical are wanted, 5 grains 
of the substance must be dissolved in 120 grains of water ; the 125 
grains of solution will measure slightly more than 2 fluidrachms, 
but the excess, which is slight, can be rejected. If 8 fluidounces of 
a 10 per cent, solution are wanted, 4100 grains of solution must be 
made by using 410 grains of the medicinal agent and 3690 grains 
of water ; 8 fluidounces of water weigh 3646 grains, hence the ex- 
cess of solution will not be large. If a quart of 1 per cent, mercuric 
chloride solution is desired, 15,000 grains of solution must be made, 
as the weight of a quart of water is 14,583 grains, which is only 
267 grains less than the quantity of water necessary ; 150 grains of 
mercuric chloride dissolved in 14,850 grains of water yield only a 
little over J fluidounce more of the solution than is wanted. If 
500 Cc. of a 5 per cent, solution are desired, 530 Gm. of the solu- 
tion must be made, the excess of solution being 4.5 Cc, for 5 per 
cent, of 530 is 26.5, and as each Cc. of water equals 1 Gm., 530 
— 26.5 = 504.5. When solvents other than water are used, having 
a higher or lower specific gravity, due allowance must be made for 
this fact, as also when strong solutions of substauces likely to increase 
the volume are to be prepared. 

The liquids used as solvents or menstrua in pharmacy, are water, 
alcohol, ether, vinegar, glycerin, and occasionally fixed and essential 
oils; each of these fluids has a specific action, and their use gives 
rise to different classes of solution designated as infusions, tinctures, 
wines, etc. Water is more extensively employed than any other 
solvent ; nearly all the salts of the alkalies, earths, and metals are 
dissolved by it, together with a large number of vegetable acids and 
the salts of the alkaloids. Alcohol is an excellent solvent for vege- 
table substances, such as resins, volatile oils, glucosides, and alka- 
loids ; it also possesses valuable negative properties, since it does not 
dissolve gum, starch, and albumen, which impair the stability of 
aqueous solutions. The combined solvent powers of alcohol and 
water are utilized in the form of diluted alcohol and wine as a men- 



116 GENERAL PHARMACY. 

struum for numerous liquid vegetable preparations. The use of 
Ether is coufined to solutions of fixed oils and fats, volatile oils and 
resins, and a few alkaloids and neutral principles. Glycerin is chiefly 
employed to insure the permanency of vegetable solutions when the 
use of alcohol is contra-indicated ; it is also an excellent solvent for 
the tannins, pepsin, and some mineral salts and vegetable acids, 
and forms the basis of a valuable class of solutions known as 
glycerites. 

Complete solution is generally aimed at in pharmacy in the case 
of inorganic solids, but is frequently impossible with substances of 
vegetable origin. 

The process of treating a mixture of soluble and insoluble mineral 
substances with solvents which only partially dissolve them is termed 
lixiviation or leeching, and is extensively practised in the arts ; as an 
example may be cited the leeching of ashes of wood and marine 
plants for the purpose of dissolving out the alkali carbonates, iodides, 
etc. The various methods of partial solution applied to mixtures of 
soluble and insoluble vegetable matter are usually comprised under 
the general term "extraction," but have received specific names, such 
as infusion, decoction, maceration, digestion, and percolation. 

The process of Infusion is understood to represent the solvent 
action of boiling water, on vegetable drugs, duriug the time occupied 
in cooling ; it may be varied, as to a longer or shorter period of time, 
according to the degree of extractibility of the principles to be dis- 
solved, and should always be conducted in closed vessels. The sub- 
stance to be infused should be in a coarse state of division and 
preferably suspended in the liquid. Decoction represents the solvent 
action of fluids at their boiling temperature, and is confined to drugs 
not yielding their active virtues at a lower temperature and where 
no loss of volatile principles need be feared. Maceration consists in 
subjecting a mixture of soluble and insoluble matter in a divided 
state to the solvent action of fluids at the common temperature for 
such length of time as may be necessary to insure complete solution 
of the principles sought ; the process must be conducted in well- 
closed vessels, and the contents must be well shaken at least once in 
twenty-four hours. Frequent agitation is essential if complete ex- 
traction of soluble matter is to be insured by maceration, as other- 
wise a dense layer of a concentrated solution will soon envelop the 
material and prevent the solvent action of the menstruum from being 
eifective ; hence only a small proportion of the soluble constit- 
uents will be taken up, as may be readily observed in the slight 
color and odor of the supernatant liquid, if a mixture of asafetida 
and alcohol, or of opium and water, be set aside for a week without 
agitation. Digestion differs from maceration only in the higher 
degree of temperature employed, it being constant during the pro- 
cess, the use of which is confined to substances of very close texture. 



CHAPTER VIII- 

PERCOLATION. 

Percolation, or, as it is sometimes called, displacement, is beyond 
doubt the most important method of solution or extraction in the 
hands of the pharmacist. The term percolation (from the Latin 
words per and colo, meaning to strain or trickle through) may be de- 
fined as a process whereby the soluble constituents of vegetable drugs 
are extracted by allowing the menstruum to permeate a column of 
the powdered material, the saturated solution, as fast as formed, being 
removed, thus continually presenting fresh solvent to the drug. The 
apparatus in which the process is carried on is known as the perco- 
lator, the solution obtained as the pjereolate, and the residue of insol- 
uble matter as the mare. 

Although the idea of solution by percolation did nut originate in 
this country, its present improved and general application is due 
entirely to American enterprise and ingenuity. The first attempt to 
extract soluble matter from powdered drugs by allowing a menstruum 
to exert its solvent action during its passage through a column of the 
material was made by Count Real in the early part of the present cen- 
tury, the principle involved being about the same as that utilized by 
the French in the preparation of their world-renowned coffee. In 1833, 
M. Boullav, an enterprising French pharmacist, considerably modified 
the plan of Count Real, and in a series of carefully conducted experi- 
ments demonstrated the adaptability of the process of percolation to 
the extraction of vegetable drugs. So convincing were the results of 
his investigations that Prof. Procter and A. Duhamel, prominent 
American pharmacists, became deeply interested in the work, aud in 
1839 strongly advocated its adoption as a method of extraction supe- 
rior to others known at that time. Although the process of percolation 
was recognized in the United States Pharmacopoeias of 1840 and 1850, 
it did not meet with the general favor since accorded it until Prof. 
Israel Grahame, of the Maryland College of Pharmacy, in 1858, sug- 
gested some valuable improvements, which led to better results than 
had yet been obtained. To Prof. Grahame belongs the credit of first 
advocating the use of powders of uniform degree of fineness as well 
as the proper moistening of the powdered drug with a sufficient 
quantity of the menstruum before packing it in the percolator, both 
of which suggestions are now considered indispensable to successful 
percolation ; at the same time, the use and advantage of a common 
funnel for the percolation of many drugs was pointed out. The 
advantage of properly moistening the powdered drug before packing 



118 GENERAL PHARMACY. 

will be readily understood when it is considered that the material to 
be operated upon is not a mere mechauical mixture of soluble and 
insoluble matter, but that the soluble principles to be extracted are 
intimately held or enclosed by the insoluble cellular tissue, and that 
penetration of the tissue by the menstruum is necessary to effect solu- 
tion ; the saturation of the powder with the liquid prepares the con- 
stituents for ready solution and establishes an affinity between the 
cellular contents and the fresh menstruum, enabling the latter to per- 
meate the cells by osmotic action. If the menstruum is brought in 
contact with dry powder, absorption of the former either takes place 
very slowly or is entirely interfered with, just as dry, hard sponge 
resists the entrance of water for a long time ; the original moist con- 
dition of the drug before it was powdered must therefore be re- 
established before the meustruum can exercise its power of extraction. 

The principle underlying the process of percolation may be stated 
as follows : A solvent or menstruum, poured on the top of a mass of 
powder consisting in part of soluble matter, supported on a porous 
diaphragm in a cylindrical or conical vessel, descends from layer to 
layer by reason of its own gravity and the pressure of the superin- 
cumbent liquid, penetrating the particles of powder by reason of 
surface action, and exercising its solvent power on each successive 
layer until its power of solution is exhausted, after which it continues 
its downward flow, as a saturated solution, into the receiving vessel 
below. This process continues until all soluble constituents have 
been removed from the powder, the descending menstruum becoming 
less and less charged with extractive matter. To insure such complete 
extraction it is absolutely necessary that the material operated upon 
shall be in a uniform powder and that the capillarity or porosity of 
the mass be not interfered with in any way, so that the descent of the 
menstruum may be slow, even, and regular from one horizontal layer 
to the next. 

Different styles of percolators have been proposed at various times, 
and as drugs vary in their nature and require different treatment to 
yield different preparations, the pharmacist must be supplied with a 
variety of percolators, from the conical shape of the ordinary funnel 
to the nearly cylindrical. The choice of percolator depends largely 
upon the character of the percolate to be obtained, and also upon the 
nature of the drug ; for instance, if a very strong solution is to be 
prepared with a minimum quantity of menstruum, a narrow cylin- 
drical percolator is preferable, so that the solvent is made to pass 
through a long column of the drug and thus become thoroughly 
saturated ; a cylindrical, or only slightly tapering, percolator is also 
indicated when the menstruum is strongly alcoholic, or when ether 
or some other volatile liquid is used for extraction. Figs. 93 and 94 
represent two very useful percolators for the preparation of fluid 
extracts and tinctures. If, on the other hand, the quantity of drug 
to be extracted is small in proportion to the menstruum, as in the 
majority of official tinctures, a wider percolator, of the shape and 



PERCOLATION. 



119 



style shown in Fig. 95, may be used, in which the liquid will 
traverse the column of drug more rapidly and yet be able to exhaust 
it thoroughly, owing to the larger amount of menstruum at the 
disposal of the operator. When drugs such as gentian, senega, 
rhubarb, orange-peel, and others, which have a tendency to swell 
considerably, particularly with aqueous or feebly alcoholic men- 
strua, are to be percolated, a common funnel will often be found 



Fig. 93. 



Fig. 94. 





Glass percolator described in the U. S. Pharm.. 1890. 



The Oldberg percolator. 



advantageous on account of the ample allowance for lateral expan- 
sion of the moist drug. The size of the percolator selected should 
be in proportion to the quantity of drug to be extracted; when 
properly packed in the percolator the drug should not occupy more 
than two-thirds of its height. 

The common tin percolator (Fig. 96) consists of a cylinder vary- 
ing in size and tapering somewhat toward the funnel-shaped end, 
provided with two perforated diaphragms fitting loosely into the 
cylinder, the lower of which should be more finely perforated than 



120 



GENERAL PHARMACY. 



the upper. The stopcock in the neck of the funnel serves the 
double purpose of allowing maceration for any desired period and 
of enabling the operator to regulate the rate of flow of the percolate. 
Tin percolators caunot be used, however, for any drugs containing; 
principles liable to be affected by metal, or to be exhausted with acid 
menstrua. 



Fig. 95. 



Fig. 96. 





Ordinary glass percolator. 



Covered tin percolator with stopcock for 
regulating the flow. 



For percolation with very volatile liquids — ether, chloroform, 
and the like — a specially constructed percolator must be used (see 
Fig. 97), in which proper provision is made to prevent loss of 
menstruum and to establish communication between the vessel 
intended to receive the percolate and the space above the drug in the 
percolator, so that the air may pass upward when displaced by the 
percolate in the receiving jar ; this latter provision is essential to 
successful percolation. As may be seen from the illustration, the 
percolator is fitted air-tight to the receiving vessel by being passed 
through a cork, and loss of menstruum at the top is prevented by a 
water-joint with which the cover of the percolator forms an air- 
tight connection. The air is carried up outside of the percolator, 
and made to enter at the top, to take the place of menstruum pass- 



PERCOLATION. 



121 



Fig. 



ing downward through the drug. Fresh menstruum may be sup- 
plied through the opening in the cover without disturbing the water- 
joint. Another plan to provide for the upward displacement of the 
air from the receiving jar is to pass a tube through the centre of the 
percolator and extending below the lower 
diaphragm, the drug being packed around the 
tube ; such an arrangement is shown in the 
tin percolator, Fig. 98, which is likewise pro- 
vided with a water-joint, and the exit tube of 
which should also pass air-tight through a 
cork in the neck of the receiving vessel. An 
arrangement of tubing on the outside, as seen 
in Fig. 97, may be attached to any percolator 
capable of being closed air-tight at the top 
with a cork. 

In 1874 the Dursse percolator was intro- 
duced (see Fig. 99). It combines the advan- 
tages of a broad cylindrical and a conical ves- 
sel, and is admirably adapted for quantities 
of drug ranging from 400 to GOO Gm. Un- 
fortunately but one size is made of this pat- 
tern, which is 15 inches in length, 5 inches 
in diameter at the top and 1 inch at the begin- 
ning of the outlet tube. One of these per- 
colators was in use almost weekly, during 
eighteen years, in the author's hands, and many 
a pound of mix vomica, cinchona, ergot, gin- 
ger, vanilla, gentian, rhubarb, valerian, etc., 
was successfully extracted therein during that 
time. Its chief merits lie in the perfect uni- 
formity of its sides and its accurately fitting 
cover, by which the now of the liquid can be 
regulated and all volatilization of menstruum 
be prevented. Being made of heavy glass it 
bears usage very well and is not easily 
broken. 

Manufacturers who operate upon large 
quantities of drugs, varying from 25 to 500 
pounds or more, employ percolators made of 
heavy tin or tinned copper. Such percolators 
are usually of the shape shown in Fig. 100, and supported in an 
adjustable frame, or are cut off flat at the point where the funnel- 
shaped end begius, and supported on a heavy wooden stand. In 
the latter shape, the drip-cock is situated on the side of the per- 
colator, near the bottom. These large percolators are provided 
with two diaphragms or perforated disks, likewise made of heavy 
tin ; the one is placed about eight or ten inches from the bottom, 
and is usually covered with a piece of muslin before the moistened 




c.c. 

2000 
1800 
1600 
1400 
1200 
1000 
800 

500 

300 

200 ~ 
100 



Glass percolator for use with 
volatile menstruum. 



122 



GENERAL PHARMACY. 



drug is introduced, while the other diaphragm is inserted over the 
mass of drug, which has been previously covered with a piece of 
felt or flannel, to insure uniform distribution of the menstruum. In 
order that the descent of the menstruum may be regular and un- 
interrupted during maceration of the drug, a tube attached to the 
inner side of the percolator, connects the space below the lower 
diaphragm with the space above the upper disk, and thus allows the 



Fig. 98. 



Fig. 





Tin percolator for volatile liquids. 



The Dursse percolator. 



air from below to displace the menstruum above. A well- fitting 
cover, as shown in the illustration, prevents evaporation of alcohol 
and admits fresh menstruum when desired. 

The well-known siphon or well-tube percolator, first suggested in 
1872 by Dr. E. R. Squibb, is still in constant use in his laboratories ; 
the principle involved, with slight modifications, has been adopted in 
the official directions for percolation in the United States Pharmaco- 
poeia for 1880 and 1890. The Squibb well-tube percolator, as shown 
in Figs. 101 and 102, is constructed upon the principle of an artesian 
well, the moistened drug representing the soil through which the men- 
struum passes very slowly, the solution or percolate, rising in the well- 
tube which passes through the centre of the mass, being finally drawn 



PERCOLATION. 



123 



Fig. 100. 



Fig. 101. 





Copper percolator, tinned inside. 
(Capacity, 20 to 100 gallons.) 



Squibb's well-tube percolator, 
made of glass. 



Fig. 102 




Sqnibb's well-tube percolator, made of stoneware. 



124 



GENERAL PHARMACY 



Fig. 



off by means of the glass siphon. The process is completely under 
the control of the operator as regards the rate of flow of the percolate 
and maceration of the mass to any desired extent. To prevent par- 
ticles of drug from entering the well-tube, this is made to rest on 
several disks of flannel, through which the percolate must pass before 
it can enter the tube. The siphon acts automatically after it has once 
been started, and cannot exhaust itself, because, when the 
liquid in the percolator falls to the level of the turned- 
up end of the outer limb of the siphon, the flow ceases, 
leaving the siphon-tube full of liquid, the difference in 
the length of the two limbs of the siphon being only 
such that the inner limb reaches the bottom of the well- 
tube, and when measured on the outer limb, reaches to 
one-half of its turned-up end. The pressure on the sur- 
face of the moistened drug being duly counterbalanced 
by the atmospheric pressure on the column of percolate 
in the well-tube and siphon, all particles of the mass in 
the percolator will be subject to uniform pressure ; thus 
the gravitation of the liquid is used to best advantage, 
just as in the case of the rubber tube recommended in 
the pharmacopceial directions for percolation. The body 
of the percolator is made of glass or stoneware, and the 
evaporation of menstruum is prevented by a tightly- 
fitting cover of sheet rubber about \ inch thick. 

During the past ten or twelve years much has been 
written about " pressure percolators," the chief claim 
advanced for their use being the complete extraction of 
drugs with less menstruum than by ordinary methods, 
which applies to the preparation of concentrated solu- 
tions, such as fluid extracts. The idea of more complete 
solution by means of pressure originated with Count 
Real about 1815, and the apparatus devised by him (see 
Fig. 103) bears a close resemblance to some of the pres- 
sure percolators of the present day, devised by Rosen- 
wasser, Berry, Suit, and Anderson. In the new apparatus 
the drug' to be extracted is confined, by means of a suit- 
able screw arrangement, between perforated disks, in any 
desired space, without the possibility of expansion on 
coming in contact with the bulk of the menstruum. 
The solvent is forced through the mass by pressure 
obtained from a column of liquid 10 or 12 feet in height, 
supplied by a reservoir. 
Management of the Process of Percolation. The Pharmacopoeia 
gives the following directions for conducting percolation, which are 
applicable to all official preparations in which this method of solu- 
tion is indicated, as in each individual case the fineness of powder, 
the quantity of menstruum to be used for moistening the drug, and 
the degree of firmness with which it is to be packed, are specified : 



The " Count 
Real" pressure 
percolator. 



PERCOLATION. 125 

"The percolator most suitable for the quantities contemplated by 
the Pharmacopoeia, should be nearly cylindrical or slightly conical, 
with a funnel-shaped termination at the smaller end. The neck of 
this funnel end should be rather short, aud should gradually and 
regularly become narrower toward the orifice, so that a perforated 
cork, bearing a short glass tube, may be tightly wedged into it from 
within until the end of the cork is flush with its outer edge. The 
glass tube, which must not protrude above the inner surface of the 
cork, should extend from 3 to 4 Cm. beyond the outer surface of the 
cork, and should be provided with a closely-fitting rubber tube, 
at least one-fourth longer than the percolator itself, and ending in 
another short glass tube, whereby the rubber tube may be so sus- 
pended that its orifice shall be above the surface of the menstruum in 
the percolator, a rubber band holding it in position. 

"The percolator is prepared for percolation by gently pressing a 
small tuft of cotton into the space of the neck above the cork, and a 
small layer of clean and dry sand is then poured upon the surface of 
the cotton to hold it in place. 

" The powdered substance to be percolated (which must be uni- 
formly of the fineness directed in the formula, and should be per- 
fectly air-dry before it is weighed) is put into a basin, the specified 
quantity of menstruum is poured on, and it is thoroughly stirred with 
a spatula or other suitable instrument until it appears uniformly 
moistened. The moist powder is then passed through a coarse 
sieve — Xo. 40 powders, and those which are finer, requiring a Xo. -0 
sieve, whilst Xo. 30 powders require a No. 15 sieve for this purpose. 
Powders of a less degree of fineness usually do not require this ad- 
ditional treatment after the moistening. The moist powder is now 
transferred to a sheet of thick paper and the whole quantity poured 
from it into the percolator. It is then shaken down lightly and 
allowed to remain in that condition for a period varying from fifteen 
minutes to several hours, unless otherwise directed; after which the 
powder is pressed by the aid of a plunger of suitable dimensions, 
more or less firmly in proportion to the character of the powdered 
substance and the alcoholic strength of the menstruum ; strongly 
alcoholic menstrua, as a rule, permitting firmer packing of the pow- 
der than those weaker. The percolator is now placed in position for 
percolation, aud the rubber tube having been fastened at a suitable 
height, the surface of the powder is covered by an accurately fitting 
disk of filtering paper or other suitable material, and a sufficient 
quantity of the menstruum poured on through a funnel reaching 
nearly to the surface of the paper. If these conditions are accurately 
observed the menstruum will penetrate the powder equally until it 
has passed into the rubber tube, and has reached in this a height 
corresponding to its level in the percolator, which is now closely 
covered to prevent evaporation. The apparatus is then allowed to 
stand at rest for the time specified in the formula. 

" To begin percolation, the rubber tube is lowered and its glass 



126 



GENERAL PHARMACY. 



end introduced into the neck of the bottle previously marked for the 
quantity of liquid to be percolated, if the percolate is to be measured, 
or of a tared bottle if the percolate is to be weighed ; and by raising 



Fig. 104. 




or lowering this recipient the rapidity of percolation may be increased 
or lessened as may be desirable — observing, however, that the rate of 
percolation, unless the quantity of material taken in operation is 
largely in excess of the pharmacopceial quantities, shall not exceed 



PERCOLATION. 127 

the limit of ten to thirty drops in a minute. A layer of menstruum 
must constantly be maintained above the powder, so as to prevent 
the access of air to its interstices, until all has been added or the 
requisite quantity of percolate has been obtained. This is con- 
veniently accomplished, if the space above the powder will admit of 
it, by inverting a bottle containing the entire quantity of menstruum 
over the percolator iu such a manner that its mouth may dip beneath 
the surface of the liquid, the bottle being of such a shape that its 
shoulder will serve as a cover for the percolator. (For illustration 
of the official process, see Fig. 104.) 

" When the process is successfully conducted, the first portion of 
the liquid or percolate passing through the percolator will be nearly 
saturated with the soluble constituents of the substance treated ; and 
if the quantity of menstruum be sufficient for its exhaustion, the last 
portion of the percolate will be destitute of color, odor, and taste 
other than that possessed by the menstruum itself/' 

The degree of fineness of powder to which a drug is to be reduced 
depends partly upon the menstruum to be used and partly upon the 
nature of the active constituents of the drug and the readiness with 
which these can bo extracted. Drugs like aconite, cinchona, mix 
vomica, vcratrum viride, and others, require to be in fine powder, 
while gentian, rhubarb, krameria, squill, and the like, can be readily 
exhausted in coarser powder. As a rule, strongly alcoholic or ethereal 
menstrua are used with fine powder, whereas hydro-alcoholic and 
aqueous menstrua are better adapted to coarser powders. 

The quantity of menstruum to be used for moistening the powder 
also varies with different drugs; one-fourth to one-half as much 
menstruum as powder is generally required to thoroughly dampen it 
without destroying its mobility, depending likewise upon the nature 
of the drug and menstruum. In a few cases, where the active con- 
stituents are quickly extracted, and previous moistening might cause 
the powder to agglutinate, as in tincture of catechu and the official 
oleoresius, it is even better not to moisten the drug at all before 
placing it in the percolator. 

The next step is the proper packing of the percolator, and upon it 
will largely depend the success of the process. A suitable support 
must be provided for the moistened powder, and for this purpose a 
notched cork or a tuft of absorbent cotton may be used. If the cork 
be chosen a layer of cotton should be placed over it to prevent the 
escape of powder, or if cotton alone be used, it may be slightly com- 
pressed into the neck of the percolator. Unless the quantity of drug 
be large, the moistened powder, after having been first passed through 
a coarse sieve to break up any lumps, should be transferred to the per- 
colator all at one time, and then shaken down by tapping the sides of the 
vessel. If the drug is to be saturated with menstruum before macera- 
tion, as in the case of fluid extracts, the powder should be at once com- 
pressed, moderately or firmly as the character of the menstruum and 
the nature of the drug may require. As a rule, fine powders and alco- 



128 



GENERAL PHARMACY. 



Fig. 105. 





holic menstrua demand firm packing, as also ligneous and spongy drugs 
under certain conditions ; aqueous menstrua generally necessitate mod- 
erate compression. If the moistened drug be introduced in layers, uni- 
form packing becomes more difficult ; the lower portions of the drug 
should be less firmly compressed than the upper layers, because the 
menstruum, when it reaches them, being already charged with some 
soluble matter, is denser than at the top, and hence cannot penetrate 
a firmly packed mass as readily as would fresh menstruum. Macera- 
tion of the moistened powder prior to percolation is advantageous in 
many cases, as it allows the drug to swell and become more thoroughly 
permeated by the menstruum, and permits more satisfactory packing 
afterward ; in some cases, where concen- 
trated solutions are desired, maceration after 
saturation is positively necessary to insure 
good results. The packing of the moistened 
powder is best effected with a packing stick 
of suitable design, made of hard wood, of 
the shape of the well-known potato-masher. 
Next to uniformity in fineness of powder, 
uniformity in packing is the most important 
feature in percolation, so as to insure the 
even descent of the menstruum ; if the drug 
is more firmly compressed on one side than 
on the other, the menstruum is sure to flow 
in the direction of least resistance, and leave 
a part of the mass imperfectly extracted. 
After the powder has been packed, a dia- 
phragm of filtering paper or felt is laid 
over the surface and kept in place by means of pebbles or pieces of 
broken glass ; this is for the purpose of preventing disturbance of the 
upper layer and to insure equal distribution of the liquid when the 
menstruum is poured on. 

As stated in the pharmacopoeial directions, a layer of menstruum 
must constantly be maintained above the powder, in order to prevent 
the access of air to its interstices. Every percolator should be pro- 
vided with a cover, which may be either of glass or sheet-rubber, to 
avoid loss of or change in the menstruum. 

The simplest arrangement for controlling the rate of flow of the 
percolate is by means of a rubber tube, as specified in the official 
directions, and this device can be attached to nearly every form of 
percolator known. As the rate of flow from the tube will be pro- 
portionate to the difference in height between the liquid in the per- 
colator and the point to which the tube is raised on the outside, it is 
evident that its control is within easy reach aud may be varied from 
a constant stream to five drops per minute. The rapidity with which 
the percolate shall be allowed to pass will vary with the object in 
view and the ease with which the active principles enter into solu- 
tion ; for tinctures, the average rate may be stated to be 15 to 20 



Glass receiving jar, graduated 
in U. S. fid. measure. 



PERCOLATION. 



129 



Fig. 106. 




drops per minute, while the percolate in the ease of fluid extracts 

should not be allowed to flow taster than 5 or 10 drops per minute. 

The complete exhaustion of a drug can 

only be judged by the physical properties 

of the last portions of the percolate ; heuce 

a thorough knowledge of the valuable con- 
© © 

stituents sought to be extracted is essential ; 
absence of color and odor is not always 
indicative of perfect exhaustion, and the 
sense of taste furnishes a more reliable test 
in the case of aconite, ginger, mix vomica, 
etc. Drugs like jalap and podophyllum are 
known to be exhausted when the percolate 
mixes clear with water, as this will not 
occur until all resin has been extracted. 
Cardamom, valerian, vanilla and similar 
aromatic drugs are judged entirely by the 
odor of the percolate ; quassia, rhamnus 
and gentian, by the bitter taste; and rhatany, 
catechu and geranium, by the peculiar astrin- 
gency of their soluble constituents. 

A considerable quantity of alcoholic men- 
struum is sometimes retained by the marc 
after exhaustion of the drug, and this may 
be recovered by expression or by percolation with water, either direct 
or after admixture of cleau sawdust. Such recovered alcohol is unfit 
for further use until it has been purified 
by adding three grains of potassium per- 
manganate to every pint, shaking the mix- 
ture occasionally during several days, and 
then decanting and distilling. Another plan 
to avoid the loss of alcohol by absorption is 
to employ gradually weaker menstrua, after 
the required quantity of original menstruum 
has all been added. 

Much time and annoyance may be saved 
by collecting the percolate in properly grad- 
uated glass jars (if the percolate is to be 
weighed, use tared vessels), which can be ob- 
tained from glass manufacturers in different 
sizes adjusted both for apothecaries' and 
metric fluid measure (see Figs. 105 and 106). 
A convenient plan also is to paste a strip of 
paper on a wide-mouth bottle and mark on 
the same with ink the different quantities 
of liquid measured into the bottle, as shown 
in Fig. 107 ; to protect the paper scale and 

render it impervious to moisture, it should be coated with some 
colorless varnish. 



Glass receiving jar, graduated 
in metric fid. measure. 



Fig. 107 




Graduated glass receiving jar. 
home-made. 



130 



GENERAL PHARMACY. 



The usual method of supporting percolators is by means of the iron 
rings of a retort-stand, as already shown in Fig. 104 ; in order to pro- 
tect the glass, sections of rubber tubing may be attached to the rings, 
forming: suitable cushions or guards. A verv convenient arrangement 
is Beck's Percolating Stand (see Fig. 108), which admits of simulta- 
neous multiple operations and is equally well adapted for use in the 
'store or laboratory. The stand can either be placed on the floor or 
be supported on two iron brackets fastened to the wall ; as shown in 



Fig. 108. 




Beck's percolating stand. 

the illustration, it can be changed by means of thumb-screws to suit 
various heights of bottles. The length of the base-board is 42 
inches, the width 12 inches, and the extreme height of the stand 
36 inches ; the supports for percolators and funnels are formed by 
means of cross-pieces suitably hollowed out and secured by screws 
passing through the slot in the cross-bars. 

Re percolation is a process intended for the preparation of con- 
centrated vegetable solutions with a minimum quantity of menstruum, 
and is confined to the manufacture of fluid extracts without heat. 
Dr. Squibb, who is the author of the processs, defines it to be " the 
successive application of the same percolating menstruum to fresh 



PERCOLATION. 131 

portions of the substance to be percolated/' His suggestion was 
based upon the observation made that a weak solution of the con- 
stituents of a drug is a better solvent for the soluble active principles 
of that drug than fresh menstruum. The following example will 
serve to illustrate the process of repercolation : 1000 Gm. of a prop- 
erly powdered drug are divided into five portions of 200 Gm. each ; 
one portion is moistened, packed, macerated, and percolated to ex- 
haustion, the first 150 Cc. of the percolate being set aside as finished 
product, the remainder beiug collected in fractions of 200 Cc , and 
numbered respectively 1, 2, 3, etc., in the order in which they are 
collected. The second portion of the drug is moistened with No. 1 
weak percolate, packed and percolated to exhaustion, the different 
weak percolates being used in the order in which they have been 
collected, followed by fresh menstruum if necessary, the first 200 
Cc. of the percolate from this second portion of the drug being set aside 
as finished product, the remainder being again collected in fractions 
of 200 Cc, and numbered 1, 2, S, etc., as before. The third, fourth, 
and fifth portions of the drug are treated exactly like the second 
portion, the first 200 Cc. of the percolate in each instance being set 
aside as finished product. When the fifth portion of the drug has 
been exhausted there will be on hand five lots of finished product — 
150, 200, 200, 200, and 200 Cc. ; total, 950 Cc— and besides, four 
or five lots of weak percolate supposed to hold in solution the soluble 
matter from 50 Gm. ; these weak percolates, properly numbered, are 
set aside, to be again used in place of fresh menstruum for the next 
lot of the same preparation, the process henceforth being continued 
exactly as with the second portion of the drug mentioned before. This 
retention of 25 per cent, of the soluble matter of one portion of 
the drug in the weak percolates is based on numerous carefully con- 
ducted experiments, the results of which showed that when 100 Gm. 
of drug are exhausted by percolation, from 70 to 80 per cent, of the 
total soluble constituents present are contained in the first 75 Cc of 
percolate. By some the process of repercolation is termed fractional 
percolation, and modifications of Dr. Squibb's method, stated above, 
have been suggested ; in every instance, however, the same principle 
is kept in view — namely, the use of weak percolates in place of fresh 
menstruum. 

Continuous percolation is a name sometimes applied to a 
process of extraction which involves the exhaustion of a drug with 
a limited quantity of menstruum, by repeatedly vaporizing and con- 
densing the fluid in a specially constructed apparatus, so arranged 
that the extracted soluble matter remains in the receiving flask, while 
the solvent, in the form of vapor, passes upward to a reflux con- 
denser, and thence flows back into the percolator. It is chiefly 
employed in the examination of vegetable drugs, with a view of 
determining their valuable constituents, and is particularly adapted 
to the manufacture of the official oleoresins. For description of the 
apparatus see the chapter on Oleoresins. 



CHAPTEK IX. 

SEPARATION OF NON-VOLATILE MATTER. 

The process of separation may be applied to non-volatile or fixed 
as well as volatile matter ; in the former case it is understood to 
refer to the removal of insoluble substances, sediments, etc., from 
fluids holding them in suspension, and also of immiscible fluids from 
each other. The various operations employed for the separation of 
solids from fluids are termed filtration, decautation, expression, clari- 
fication, and decoloration. 

Filtration. 

By some pharmacists filtration is considered so trivial an operation 
as not to merit extended consideration ; but, like other simple pro- 
cesses, it is well deserving of study, as there is room for the exercise 
of intelligence and ingenuity in its many useful modifications. Fil- 
tration is usually employed when the solid matter to be removed is 
not present in excessive quantity, and consists in submitting the 
mixture to the separating action of certain media which allow the 
fluids to pass through but are impervious to the solid particles. 
Sometimes filtration is also called eolation or straining; but it is 
understood that the process of straining differs from filtration either 
in the less complete removal of suspended sedimentary matter from 
a fluid, or in the fact that the solid particles are not in fine powder 
and can be easily retained by coarser media than those generally 
employed for filtration. Colation is a favorite mode of separation 
when the fluid is of a viscid character. The various filtering media 
employed are cotton and woollen cloth, paper made therefrom, also 
absorbent cotton, glass, wool, asbestos, sand, and charcoal; the clear 
clear liquid passing through these media is termed the filtrate. 

For straining syrups, oils, and similar fluids, filter-bags of flannel 
or felt are admirably adapted, as they permit a rapid passage of 
the liquid, and effectually retain all solid matter ; such filter-bags 
are of conical shape, see Figs. 109 and 110, and are readily made, 
of plain or Canton flannel, by folding over a square piece in the 
manner indicated in Fig. Ill, the line c d being laid over the line c a 
and united by a seam ; the bag thus formed is pointed at c and open 
from a to 6, the line a c being lapped over to form the seam. The 
long end projecting toward the point b beyond the clotted line ef 
should be removed and four loops of heavy cord or tape attached 
after the edge has been turned over ; the loops will serve to suspend 



SEPARATION OF XOS-VOLATILE MATTER. 



133 



the filter-bag properly in a square or round frame, as shown iu Fig. 
112. For some purposes, as the straining of dense saline solutions or 



Fig. 109. 




Flannel strainer. 
Fig. 111. 




Manner of folding strainer. 



Fig. 113. 





Frame for cloth or flannel strainers, 
known as " tenaculum." 



Straining bag, showing position when in use. 



134 



GENERAL PHARMACY 



the washing and draining of bulky precipitates, a square cotton cloth 
may be stretched over a square frame called tenaculum, as shown in 
Fig. 113 ; for smaller operations, such as straining infusions or decoc- 
tions, the cloth strainer may be fastened over a funnel by means of 
wooden pinchcocks, and when it becomes necessary to strain with 
expression, the ends of the strainer must be folded over and twisted 
in opposite directions, as shown in Fig. 114. A kind of cotton cloth 

Fig. 114. 




Showing the manner of folding and expressing flannel or cloth strainers. 

known as cheese-cloth is preferred by mauy for strainers, as it allows 
liquids to pass rapidly through it. All strainers should be well 
wetted just before they are used, and those containing sizing should 
be freed from the same by washing with hot water before they are 
put into use at all. For use at the dispensing counter in straining 
solutions, a pledget of absorbent cotton placed in the throat of a 
funnel will be found very convenient and serviceable; and, as nearly 
every solution prepared is likely to contain some specks and motes, 
this little operation should never be neglected. 

Some years ago a very serviceable oil filter was devised by William 
R. Warner, which possesses the advantage of filtration under pres- 
sure, and is equally well adapted to syrups (see Fig. 115). The upper 
cylindrical vessel of tiuned iron is twenty-two inches high and ten 
inches in diameter, with a flanch rim soldered on the bottom, of 
rather less diameter and an inch wide, so as to fit firmly into the open 
top of another cylindrical vessel, B, of the same diameter, eighteen 
inches high. The upper vessel is furnished with a lid and with an 
L-shaped tube and stopcock, c, which penetrates the side close to 
the bottom, and fits into another tube, d, at e, which tube opens 
into the lower vessel close to its base, and is further secured to B by 
a tubular stay. The filtering medium is a cone of hat felt, projecting 
upward from near the bottom of the lower vessel, and secured in 
place by thumb-screws passing through two tinned-iron rings and 
the felt, which are all properly pierced for that purpose. The stop- 
cock, c, being closed, the upper vessel is fitted in its place, and the 
tube-joint, e, rendered tight by wrapping with isinglass plaster; 



SEPARATION OF XOX-VOLATILE MATTER. 



135 



when this is dry, the upper vessel is filled with the liquid to be 
filtered, and the stopcock, c, opened. The filtered liquid, as it accu- 
mulates in B, should be drawn off at /, and if convenient the appa- 
ratus should be kept in a temperature of about 120° F., in order to 
facilitate the flow of the liquid. 

Complete separation of fine suspended matter from fluids can best 
be effected by means of filtration through paper; only unsized paper 



Fig. 115. 



Fig. 116. 





A plain filter. 



fte 




Warner's oil filter. 



can be used, the best kind being that 
made from cotton and linen rags, 
although paper made from woollen 
material is tougher, and, being more 
porous, permits more rapid filtration. 
The square sheets of filtering paper, 
which at one time were the only 
style to be had, are rarely used now, 
since ready-cut round filters can be 
had of all sizes and qualities. Two 
kinds of paper filters are used, the 
plain and the plaited, the construction 
of which is very simple, and, when 
once properly understood, never forgotten. The chief advantages 
of plain filters are the simplicity of construction and the fact that 
they are admirably adapted for collecting the solid matter suspended 
in the fluid, which is afterward to be removed from the paper for 
further use; on the other hand, filtration proceeds far less rapidly 
in a plain than in a plaited filter, because the paper lies flat against 
the sides of the funnel, and the liquid passes through only at the 
point or apex. Plain filters are made by doubling a circular piece 
of filtering paper upon itself, and then folding this directly in the 
middle; by now opening the folds in such a manner that one sector 
or division shall appear on one sic|e and three sectors on the other 
side, a perfect cone will be obtained, as shown in Fig. 116, which 
will exactly fit into a properly-shaped funnel. 



136 



GENERAL PHARMACY. 



The waste of paper which is caused by this method of folding a 
plain filter, where three thicknesses of paper are found on one side 
of the filter and but one thickness on the other side, may be avoided 



Fig. n: 




Diagram for making an economical plain filter, according to E. Classen's directions. 

by following the suggestions of Edo Classen, which are as follows : 
To make a plain filter, of single thickness, which will fit a funnel 
having an angle of 60°, use a piece of filter-paper in the shape of 

Fig. 118. 




a semi-ellipse, as shown in Fig. 117, the line A B being one-fifth 
longer than the lines A C or A D. Fold the paper in the centre so 
that one-half exactly covers the other ; next fold the short straight 



SEPARATION OF NON-VOLATILE MATTER. 



137 



side over, so that both straight sides shall be of the same leogth. 
Additional security against leakage will be obtained if the strip 
last folded is again folded back upon itself, preferably toward the 
inside. 

Fig. 119. 




In order to strengthen the weakest point of the cone, a smaller 
round filter may be placed on the outside of the larger filter and 
folded with the same, or one plain filter may be placed inside of 
another, so that even thicknesses of paper shall be on all sides. 



Fig. 120. 




The construction of a plaited filter is more readily demonstrated 
than explained ; the simplest plan is to proceed as follows : Fold a 
circular piece of filtering paper twice, after the manner directed 
above for a plain filter ; this gives creases A B, A C, and A D. (See 
Fig. 118.) 

Xext fold the crease A C over on A B, and the crease A D over 
on A B ; this causes the creases A E and A F. (See Fig. 119.) 



138 



GENERAL PHARMACY. 



Now fold the crease A C over on A F, the crease A D over on 
A E, the crease A C over on A E, and the crease A D over on A F ; 
this causes the creases A G, A H, A I, and A K. (See Fig. 120.) 

The semicircle is now divided into eight sectors, all creases being 
in the same direction ; to complete the filter it is necessary to divide 
each sector into two by making a crease in a direction opposite to 
those already made — thus : (See Fig. 121.) 

Fig. 121. 




Diagram showing the creases of a plaited filter. 

Fold the triangle, A C I, back upon itself; this causes the crease, A L. 

AM. 
AN. 
AO. 
A P. 
AQ. 
AK. 
A S. 



A IE, 


a 


it 


AEG, 


a 


a 


AGB, 


u 


a 


ADK, 


it 


a 


AKF, 


a 


u 


AFH, 


a 


a 


AHB, 


it 


ic 



u 


a 


a 


u 


a 


ii 


a 


a 


a 


a 



Fig 122. 



Fig. 123. 




SEPARATION OF XOX- VOLATILE .MATTEL . 



139 



If the filter now be opened, it will be found divided into 32 sectors, 
two of which, ACL and ADP, opposite each other, show both 
edges pointing in the same direction (see Fig. 122); to prevent these 
two sectors from lying flat against the glass when the filter is placed 
in the funnel, they should be again divided by placing the index 
finger in the centre and bringing the edges up with the thumb and 
second finger, thus forming two new creases inward, A U and A V. 
(See Fig. 123.) In plaiting a filter, care must be observed that the 
creases be not pressed too firmly down to the very point, as this lias 
a tendency to rupture the paper, or at least, to materially weaken it. 
The plaited filter, when completed and ready for use, is divided into 
34 sectors, and appears as shown in Fig. 124. 



Fig. 124. 



Fig. 125. 





A complete plaited filter. 



A properly shaped glass funnel. 



The points of paper filters may be toughened or strengthened by 
dipping them into strong nitric acid of 1.42 sp. gr, and then wash- 
ing well with water to remove excess of acid; while a similar treat- 
ment with sulphuric acid converts unsized paper into parchment 
paper, which is impervious to water. Nitric acid simply toughens the 
paper, but in no wise interferes with the absorption and passage of 
fluids through it, though its power of resistance is increased tenfold 
by this treatment. 

"When the object of filtration is to obtain a clear fluid irrespective 
of the solid matter removed, a plaited filter is always to be preferred 
to the plain one, as it exposes the entire surface of the paper to the 
liquid and allows the latter to pass through very rapidly. 

Glass, porcelain, or metallic funnels, intended as supports for 
paper filters, should be of the shape shown in Fig. 125, having 



140 



GEXERAL PHARMACY. 



straight sides at an angle of 60° to each other, and the end of the 
tube being cut off obliquely, so as to compel the liquid to flow from 
one point only ; when used over a jar or beaker it is well to place 
the lower end of the funnel in contact with the side of the vessel, 
thus preventing any annoyance from splashing of the liquid. In 
order to provide for the necessary escape of air from the receiving 
vessel, whenever a funnel is placed in a bottle a piece of twine or a 
strip of paper should be placed between the neck of the bottle and 
the tube of the funnel, the end of which should invariably project 
below the neck of the bottle. 

When a paper filter is placed in a funnel, its upper edges should 
never quite reach to the rim of the funnel (better one-half inch below), 
so as to allow the funnel to be covered with glass or sheet-rubber, for 
the purpose of keeping out dust and preventing evaporation ; besides, 
if the filter projects beyond the funnel, considerable liquid will be 
drawn to the upper edges, owing to the capillarity of the paper, and 
evaporated, thus entailing loss. In pouring a liquid into a filter, it 
should never be allowed to fall in a stream upon the apex or point, 
which is likely to break from the sudden force, but should be directed 
against the side by means of a guiding-rod, as shown in Figs. 126 
and 127. 



Fig. 126. 



Fig. l: 




Manner of pouring liquids into a, filter with the aid of a guiding-rod. 



To insure a continuous supply of liquid to the filter, a bottle con- 
taining the fluid may be inverted over the funnel, in the manner 
shown in Fig. 101, for supplying menstruum to a percolator. 

For filtration of very volatile liquids, a glass tube, bent as in 
Fig. 128, may be placed under the filter against the side of the 
funnel ; the twisted end will prevent the tube from slipping down, 



SEPARATION OF XOX-VOLATILE MATTER. 



141 



Fig. 128. 



and air from the receiving-bottle can readily pass up th rough the 
tube, which should reach a little above the paper filter. The funnel, 
which should pass air-tight through a cork, must 
also be closed hermetically at the top. 

Occasionally the filtration of substances which are 
not fluid at ordinary temperature becomes necessary, 
such as mutton suet, wax, petrolatum, ointments, etc.; 
this can be effected either by means of a hot-air funnel 
or a water-bath funnel. When hot air is to be used, 
the funnel containing a filter is suspended by means 
of porcelain strips, in a heavy tin jacket, which is 
surrounded by a copper cylinder, and heat is sup- 
plied from a circular low-power burner, as shown 
in Fig. J 29, the heated air continually circulating 
around the funnel. The water-bath funnel consists of 
a glass funnel surrounded by a double tin or copper 
jacket, as shown in Fig. 130; the opening, «, at the 
top of the jacket is for the purpose of introducing hot 
water, and the projecting tube, c, near the bottom, for keeping up 
the heat of the water by means of a spirit lamp or gas jet. The 
projecting rim, e, is intended to prevent any water, running over 




Glass tube with 
twisted end. 



Fig. 129. 



Fig. 130. 




Hot-air funnel. (L.Meyer.) 



Sectional view of hot-water funnel with cover. 



at a, from entering the bottle or vessel, in the mouth of which the 
neck of the funnel may be placed. The substance to be filtered 



142 



GENERAL PHARMACY. 



should first be completely melted and then poured into the filter 
contained in the previously heated funnel, which must be kept 
covered to avoid loss of heat. 



Fig. 131. 
Water 



FIG. 132. 



41 



jfs- 



Foam 
Richard's filter pump. 

Fig. 133. 




Chapman's filter pump. 
Fig. 134. 




Geissler's glass filter pump. 



Portable filter pump, with manometer. 



The rate of filtration of a liquid can be greatly increased by ex- 
hausting the air from the funnel-tube and receiving-bottle, thereby 
increasing the atmospheric pressure above the liquid ; the necessity for 
this operation occurs more frequently in the analyst's laboratory than 
with pharmacists, yet an acquaintance with the apparatus employed 



SEPARATION OF NON-VOLATILE MATTER. 143 

is desirable. The exhaustion of the air is effected by means of an 
aspirator connected with a water supply and with the receiving- 
bottle by rubber tubing. Figs. 131, 132, 133, and 134, represent 
different styles of filter pumps ; as seen in two of the illustrations, 
suction of air is produced by forcing water, under pressure, through 
a contracted space which communicates with the air to be aspirated. 
The internal construction of the pump shown in Fig. 134 is similar 
to that of the other two, but the water which enters at w is discharged 
at D on the side ; hence this apparatus can be used at any desired 
point, beiug connected by means of tubing with the water supply 
and sink : with air-tight connections a nearly absolute vacuum can 
be obtained, as may be seen from the indications of the mauometer 
attached to the top of the pump. Whenever filter pumps are used, 
the pressure on the liquid filtering becomes so great as to endanger 
the safety of the filter point ; an extra support is therefore provided 
in the shape of a finely perforated platinum cone set in the throat 
of the funnel in which the paper cone is placed. 

When an aspirator or filter pump is used in conuection with water 
drawn from the city supply, a very annoying accident sometimes 
happens when the water pressure is suddenly reduced, or when the 
pump is cut off; namely, that a portion of water is drawn up into 
the vessel from which the air is being aspirated ; this can be guarded 
against either by interposing another vessel between the pump and 
the aspirated vessel, or by introducing into the tube connecting the 
pump and vessel a safety-valve as designed by Wislicenus, and shown 
in Fig. 135. It consists of two glass tubes of peculiar shape fitting 
snugly into each other at /, the bulb being well coated with resin 
cerate ; the tube b is fitted into the rubber tube attached to the pump, 
and the tube a into the tube attached to the vessel. At r a solid 
soft-rubber ring rests in the upper part of the tube b, and closes the 
same air-tight as soon as suction is established ; while at there is an 
opening in the closed end of the tube A, which is covered with thin 
sheet-rubber, as shown in Fig. 135. As soon as the suction of air 
ceases from any cause, the opening at o is tightly closed by the 
rubber, and no w r ater can enter. If any water is drawn up into B, it 
is emptied by withdrawing the tube A, the rubber ring becoming 
loose. 

For rarefying the air under filters when water pressure is not 
available, a simpler contrivance may be resorted to, as shown in Fig. 
136 : the water flowing from the upper to the lower bottle with- 
draws air from the receiving-flask, and by simply changing the bot- 
tles when the upper one becomes empty, the operation mav be 
continued for any length of time, the air-tube being closed by means 
of a pinchcock, while the bottles are being changed. Ordinary 
five-gallon castor-oil cans may be conveniently used in place of 
bottles. 

The turbidity of some liquids is caused by suspension of matter in 
so finely divided a form that its removal cannot be effected by the 



144 



GENERAL PHARMACY. 



ordinary methods of filtration, and recourse must be had to the inter- 
position of some other substance to render the liquid perfectly trans- 
parent and clear ; in such cases paper pulp, calcium phosphate, aud 



Fig. 135. 



Fig. 136. 



/ 




Fig. 135. — Wislicenus safety-valve. 

Fig. 136.— Filtering apparatus, a and b are two large bottles connected, as indicated in the 
drawing, by a narrow india-rubber tube with thick walls. The upper bottle should be placed 
as high as possible, c is a bottle into which the filtrate is to pass. The interior of this is in 
connection with a by a thick- walled tube, d. Into the stopper of c the funnel e is fixed, and at 
its apex lies a small perforated platinum cone,/, which supports the apex of the filter when 
the interior of c is partially exhausted by the discharge of the water in a into b. 



purified talcum form excellent filtering media. Paper pulp is readily 
prepared from scraps of filtering paper by treating them with hot 
water in a mortar or with active agitation in a bottle. When the 
paper has become thoroughly pulped, the excessive moisture may be 
removed by expression in a clean cloth, after which the pulp may be 
added to the liquid to be filtered and thoroughly incorporated by 



SEPARATION OF SOX-VOLATILE MATTEL. 



145 



agitation. The finely divided paper pulp forms a layer on the sur- 
face of the filter, which effectually prevents the passage of minute 
particles of insoluble matter by absorbing these into its own fibre. 
For acid liquids, finely shredded asbestos is preferable. 

Immiscible liquids can be conveniently separated from each other 
by pouring the mixture into specially constructed apparatus known 
as separators or separately funnels (see Figs. 137 and 138), and after 



Fig. 137. 



Fig. 138. 





Glass separator. ( Funnel shape.) 



Glass separator. (Globe shape. 



the liquids have separated into distinct layers by reason of their 
different specific gravities, withdrawing the lower liquid by carefully 
opening the stopcock in the tube and allowing it to flow into a 
suitable receiving vessel. 



Decantation. 

Decantation, or the process of pouring a fluid gently from one 
vessel to another, is employed in pharmacy more particularly in con- 
nection with the washing of precipitates; sometimes it is resorted to 
for the separation of immiscible liquids, but separation in such a 
case can never be so complete as by the method explained above. 

All precipitates when freshly obtained by double decomposition of 
two soluble substances, are more or less contaminated with a solution 
of the other newly-formed salt ; to remove such impurities the process 
of washing, which consists in treating the precipitate repeatedly with 

10 



146 



GENERAL PHARMACY 



fresh portions of water, is employed. Thus, when solutions of lead 
nitrate and potassium iodide are mixed, the newly-formed lead iodide 
is deposited, while potassium nitrate remains in solution, and must be 
removed before the precipitate can be dried. The thorough washing 
of precipitates is a very important operation, which may be performed 
by continued treatment with w r ater on filters and cloth strainers, or 
by allowing the liquid in which the precipitate was formed to settle 
completely in suitable vessels, decanting the clear supernatant fluid, 
addiug successive portions of fresh water, and again decanting after 
each settlement ; it is essential that the fresh water and precipitate be 
well mixed by stirring or agitation alter each addition. 

The decantatiou of a fluid is not always so simple an operation as 
it may seem; the shape and size of the vessel from which the liquid 



Fig. 139. 




Decantation with aid of a glass rod. 



is to be poured, the nature of the liquid and the height to which it 
fills the vessel, all influence the flow of the liquid. When the fluid 
to be decanted is water or an aqueous solution, and the vessel not 
very large, either with or without a lip, the simplest plan is to transfer 
the liquid with the aid of a glass rod, as shown in Fig. 139. The 
guiding-rod prevents the splitting of the current of the liquid, to 
which is due the well-known phenomenon of liquids running back on 
the sides of the vessel from which they are poured. When the vessel 
from which the liquid is to be poured is too large or too full of liquid 
to admit of decantation with the aid of a glass rod, the liquid may 
be made to flow in a somewhat contracted but solid stream by greasing 
the rim of the vessel with a little resin cerate, which prevents adhe- 
sion of the liquid to the glass and enables the force of cohesion to 
keep the particles of liquid united; Fig. 140 illustrates the operation. 



SEPARATION OF NON-VOLATILE MATTER. 



147 



Fin. HO. 



Sometimes an instrument called a siphon is employed to draw off 
the supernatant liquid from a precipitate, the method being par- 
ticularly desirable if the pre- 
cipitate is light and easily 
disturbed by handling the 
vessel ; the simple construc- 
tion of a siphon is shown 
in Figs. 141 and 142. The 
two limbs of the glass tube 
are of unequal length, the 
shorter one being immersed 
in the liquid ; it is manifest 
that if the air be entirely 
withdrawn from the tube by 
suction, the liquid will rise 
and fill the tube, owing to 
the pressure of the atmosphere 
on the surface of the liquid. 
The flow r of the liquid, having 
been started, will continue by 
reason of its downward tendency or gravitation aided by atmos- 
pheric pressure, until it falls below the mouth of the shorter limb, 
or until that in the receiving vessel rises to the level of that in 




Decantation with aid of a greased rim. 



Fig. 141. 



Fro. 1-12. 





Plain siphon. 



Glass siphon with lateral suction tube. 



the vessel from which it flows. A plain rubber tube can often be 
used with advantage as a siphon, remembering that the end of the 
tubing out of the liquid should always reach lower than that in the 
liquid, so as to insure a continuous now. 



Clarification. 

Clarification is a process of separation designed to render cloudy 
or turbid liquid transparent by means other than those thus far con- 



148 GENERAL PHARMACY. 

sidered ; it is generally effected through the agency of heat ; in every 
instance, however, the separated disturbing element must subse- 
quently be removed by filtration or decantation. The viscid character 
of some liquids renders the various methods of filtration impracti- 
cable; whereas the mere application of heat, by increasing their 
fluidity, enables the suspended particles of solid matter to separate 
spontaneously, some rising to the surface while others sink to the 
bottom ; if the liquid be allowed to remain at perfect rest while 
separation is going on, the lighter particles will form a layer, which 
can often be completely removed with the aid of a skimmer, while 
the heavy sedimentary matter is readily retained on a cloth strainer. 
Honey and balsam of fir may be treated in this manner. Saline 
solutions concentrated for the purpose of crystallization are fre- 
quently contaminated with dust and other foreign matter which 
passes freely through cloth and paper filters ; they may be readily 
clarified by adding paper-pulp (see page 144), which effectually re- 
moves the fine particles of dirt from the boiling liquid, by enveloping 
them in its own fibre and retaining them on the strainer. 

Other substances added to turbid liquids in order to effect clarifica- 
tion are egg-albumen, gelatin, aud milk. White of egg, or albumen, 
possesses the property of coagulating or solidifying when heated to 
about 80° C. (176° F.), therefore, when they are added to liquids 
and then heated, any solid matter impairing the transparency of the 
liquid will be enclosed in the coagulum formed, and can then be 
removed by straining ; some vegetable solutions prepared with cold 
aqueous menstrua contain albuminous matter originally present in 
the drug, which, upon heating to the boiling-point, is coagulated, 
and is thus gotten rid of, as in the case of extract of gentian. 
Albumen is preferably mixed with a little water before adding it to 
the liquid to be clarified, and then thoroughly incorporated with it 
before heatiug. Since albumen forms insoluble compounds with 
some plant constituents, it must be judiciously employed, lest the 
active principles contained in a liquid be removed by it. When the 
turbidity of a liquid is due to tannin, gelatin is generally preferred 
as a clarifyiug agent ; it is used like albumen, and forms insoluble 
tannate of gelatin, or leather. Milk is especially adapted to clarify- 
ing acid liquids, as the casein of the milk is coagulated by the acid, 
and thus the impurities are removed by becoming enveloped in the 
coagulum. 

Clarification of liquids may also be effected by subsidence and fer- 
mentation ; the former is often applied to fixed oils, which are 
allowed to remain undisturbed in tightly closed containers for some 
time, so that albuminous matter derived from the seed may gradu- 
ally separate and settle to the bottom. Fruit juices, as a rule, con- 
tain certain principles which tend to render them cloudy and unsightly, 
but which can be removed by fermentation at a moderate temperature, 
about 20° C. (68° F.) ; the matter thus separated settles to the bottom 



SEPARATION OF NON-VOLATILE MATT EH. 



149 



and the clear liquid may be drawn off by means of a siphon or 
otherwise. 

Decoloration. 

Decoloration, as the name indicates, is a process for the removal of 
color from liquids, and is practised on a large scale in sugar refineries. 
For pharmaceutical purposes it is chiefly confined to solutions of 
orgauic acids, alkalies, and neutral principles. The most effective 
decolorizing agent is animal charcoal, made either from bone or blood ; 
ordinary bone-black requires purification by means of hot hydro- 
chloric acid, whereby certaiu lime-salts are removed. Animal char- 
coal is preferably used in a granular condition, and its utility as a 
decolorizer depends upon its porosity ; unfortunately, charcoal also 
absorbs other matters held in solution besides color, and this may 
occasion loss of valuable constituents unless the charcoal is subse- 
quently washed with fresh menstrum. The usual method of employ- 
ing auimal charcoal is either by digesting it with the liquid to be 
decolorized, or by allowing the latter to percolate slowly through a 
column of the charcoal ; in the former case the liquid requires sub- 
sequent filtration. 

Expression. 

Expression is a process of separation which requires the exercise 
of more or less force, since it is employed in those cases where the 
amount of liquid is small com- 
pared with the quantity of solid 
matter to be removed ; as, for 
instance, in the preparation of 
fruit juices, the expression of 
macerated drugs, or the recovery 
of menstruum that may have 
been retained by the marc in 
percolation when water fails to 
force it through. For the pur- 
poses of the pharmacist, the 
tincture press, Fig. 143, and 
the Enterprise Press, Fig. 144, 
will be found very serviceable ; 
in the former the substance to 
be expressed, having been put 
into a suitable canvas or press- 
cloth bag, is placed on a per- 
forated disk in a porcelain-lined 



Fig. 143. 




Tincture press (vertical). 



iron cylinder, pressure being produced 



by means of a lever-screw 
The expressed liquid flows 



bearing upon a plate on top of the bag. 

out through the lip attached to the cylinder. The Enterprise Press 

is operated without the use of press-cloths, the material to be ex 



150 GENERAL PHARMACY. 

pressed being fed directly into the hopper communicating with a 
tapering cylinder containing a large screw, the thread of which 
gradually diminishes in size toward the smaller end ; the cylinder is 
provided with a perforated plate in the bottom, and the material is 
compressed by means of the tapering screw, which is turned with a 

Fig. U4. 




Enterprise press (horizontal). 

crank. The dry residue is discharged through an opening in the 
small end of the cylinder, and the liquid expressed flows out through 
the perforated plate. 

Another method of separation is that effected by meaus of centrif- 
ugal machines, which are extensively employed in manufacturing 
establishments for washing and drying crystals as well as for the 
rapid withdrawal of moisture in the drying of certain precipitates 
and fabrics. The apparatus used consists of a metal drum or cylin- 
der having a solid bottom but open at the top, and provided with 
perforated sides, which revolves on its own axis inside of a larger 
stationary cylinder supplied with a cover to keep out dust, and an 
outlet tube at the bottom, through which the liquid coming from the 
inner cylinder is allowed to flow out; sometimes the perforated sides 
of the inner cylinder are covered with bolting-cloth, according to the 
substance to be operated upon, and the rotary motion is imparted to 
the cylinder from below by means of steam power. The value of 
centrifugal machines depends upon the velocity with which the mate- 
rial to be centrifugal ized is hurled around and against the perforated 
sides, the revolutions usually running as high as 2000 or 3000 and 
even more per minute ; the strong draft of air created between the 
walls of the inner and outer cylinders by such rapid revolution effects 
drying of the material more thoroughly than is possible by expres- 
sion or other means. The use of centrifugal machines is based on 
the well-known laws of motion and inertia, according to which a 
body put in motion continues in a straight line unless turned from its 



SEPARATION OF SOX-VOLATILE MATTER. 



151 



path by some external force, and thus liquids can readily be sepa- 
rated from solids when a mixture of the two is dashed against a finely- 
perforated surface. In sugar re- 
fineries, centrifugal izing is the only 
suitable method known for sepa- 
rating the granulated sugar from 
■ • • i • 

the viscid mother liquor or mo- 
lasses. For special use in the phar- 
macist's laboratory, small centrifu- 
gal machines, to be operated by 
hand, have been devised ; the outer 
cylinder is usually made of enam- 
elled iron while the inner perforated 
cylinder is made of porcelain ; 

Fig. 146. 



Centrifugal separator (for hand nse) 





Centrifugal separator with cover (for hand power). 

those in which motion is supplied from above are frequently pro- 
vided with a cover for the inner cylinder, while in those operated 
from below a cover is fitted to the outer cylinder. In Figs. 145 and 
14(j are shown two styles of hand-power machines. 



Dialysis. 

Dialysis is a process of separation which differs entirely from those 
considered thus far, in not aiming at the removal of insoluble matter 
suspended in a liquid, but at bringing about a separation between 
solvents and matter held by them in solution; also between different 
kinds of matter held in solution by the same solvent. It is a prac- 
tical application of the principle of osmosis, and is due solely to sur- 
face action and the difference in diffusibility of various substances. 
The word dialysis is derived from the Greek verb StaXveiv, to 'part 



152 



GENERAL PHARMACY. 



asunder, to loose one from another, and was applied by Prof. Graham, 
of England, to the method of separation discovered by him in 1861. 
The process consists in placing a solution of the substances to be 
separated on a porous diaphragm and suspending this in pure water ; 
osmosis is established, and certain substances will pass through the 
diaphragm into solution in the water, while others will remain on the 
diaphragm, the rapidity of diffusion being in proportion to the 
strength of the solution and increasing with the rise in temperature. 
Prof. Graham discovered that crystallizable substances passed through 
the diaphragm freely, while amorphous bodies, such as gums, starch, 
gelatin, etc., either did not diffuse at all, or only very slowly ; he 
applied the name crystalloid (resembling crystals) to all substances 
thus capable of diffusion through a septum, and the name colloid 
(resembling glue or jelly) to those substauces remaining on the 
diaphragm. All colloids are amorphous or non-crystallizable, but 
all crystalloids are not necessarily capable of crytallization, as, for 
instance, hydrochloric acid, the most highly diffusible body, and 
many others. By means of dialysis, sugar can be readily separated 
from gum or starch, pepsin from peptones, iron salts from iron oxide, 
etc. Thus the process has become most valuable to manufacturers, 
whilst the analyst often finds dialysis the only means for determining 
the presence of certain substances in complex vegetable solutions, as, 
for instance, arsenous acid, corrosive mercuric chloride, or potassium 
iodide in compound sarsaparilla mixtures aud other proprietary 
medicines, where the dark color and complex nature of the solution 
preclude all other methods of separation. 

The apparatus used for dialysis is of very simple construction, as 
shown in Figs. 147 and 148. It consists of a circular glass vessel, 
with flat bottom and of convenient size, also another smaller circular 
but bottomless vessel of hard rubber or glass, having a projecting 



Fig. 147. 



Fig. 148. 





Glass dialvsers. 



rim, over which is stretched a piece of bladder, parchment, or parch- 
ment paper (see page 189). The latter constitutes the dialyser proper, 
and into it is poured the solution to be dialysed, to the depth of about 
one-half or three-quarters of an inch, after which it is floated in distilled 
water contained in the other larger vessel. In Fig. 148 the glass 
dialyser is provided at the top with a broad rim which rests upon 
the edge of the outer vessel, and thus serves as a cover to protect the 
water against dust, etc. Iu place of the foregoing convenient appa- 



SEPARATION OF NON-VOLATILE MATTER 153 

ratus, an ordinary clean hog or beef bladder may be used ; the same 
should be three-fourths filled with the solution, and then suspended 
in a large vessel of water. 

Diffusion in a dialyser will not take place unless the porous mem- 
brane or septum is in contact with water, and, moreover, its limit will 
be reached when the water on the outside becomes charged with such 
a quantity of crystalloids as to render the strength of the solution 
identical with that in the dialyser ; hence it is necessary that the 
quantity of water in the outer vessel be much greater than that of 
the liquid in the dialyser, and that it be renewed from time to time. 
The crystalloids from a 10 per cent, solution of sugar, salt, or hydro- 
chloric acid will readily diffuse through a septum if the latter is 
placed in contact with water, but no diffusion whatever will take 
place if the dialyser be floated in a 10 per cent, solution of the same 
substances. While the rate of diffusion varies greatly for different 
substances, it was found by Graham to be uniform for isomorphous 
bodies ; that is, those having exactly the same crytalline form. 

The colloidal residue remaining on the diaphragm is termed the 
dicUysate } while the solution of the crystalloids that have passed 
through the membrane is known as the diffusate. 



CHAPTER X, 

SEPARATION OF VOLATILE MATTER. 

Advantage may be taken of the volatility of some substances 
for the purpose of separation, and by their vaporization, either of the 
following objects may be attained : 

1. The separation of a volatile liquid from a solid, with a view of 
retaining the solid substance, or of one liquid from another, to obtain 
the less volatile ; in such cases the process is termed evaporation. 

2. When the separation of liquid and solid substances, by means 
of evaporation, is carried to complete dryness, the process is more 
particularly designated as desiccation or exsiccation. 

3. The separation of a volatile liquid from either a less volatile 
liquid or a solid, in order to obtain and preserve the volatilized liquid 
for future use ; the process is then known as distillation. 

4. The separation of a volatile solid from either a liquid or a solid 
which is more fixed, the object sought being the volatilized solid body ; 
this process is termed sublimation. 

Evaporation. 

In the practice of pharmacy, evaporation is extensively resorted to 
for the concentration of vegetable and saline solutions, the latter with 
a special view to subsequent crystallization, and the laws which con- 
trol the process should be well understood. Evaporation may be 
divided into four kinds; namely, evaporation over a naked fire, on 
a water-bath or steam-bath, in a vacuum apparatus, and spontaneous 
evaporation. Evaporation over a naked fire is effected by the direct 
radiation of heat from a fire, on the bottom of an uncovered dish or 
pan, and is available when the substance in solution is not injured 
by direct heat or high temperature ; it is usually employed for the 
concentration of saline solutions for crystallization, but only when 
the liquid to be vaporized is water. When evaporation at tempera- 
tures below that of boiling water is desired, the low-power burner 
shown on page 73, may be used with advantage. 

Evaporation on a water- or steam-bath is the method most fre- 
quently resorted to ; the latter can also be employed for rapid concen- 
tration of solutions at a high temperature, without the danger of 
injury from direct heat of the fire. Evaporation at temperatures 
below 100° C. (212° F.) is effected on a water-bath, and is confined 
to the surface of the liquid ; this is the method chosen for the con- 
centration of vegetable and other solutions liable to be injured by 



SEPARATION OF VOLATILE MATTER. 155 

heat at or above that of boiling water and when more volatile .sol- 
vents than water are present. Whenever a liquid is to be evaporated 
at a temperature below its boiling-point, rapidity of evaporation 
will depend upon the extent of surface exposed to the air, since 
the formation of vapor takes place only at the surface ; hence 
broad shallow vessels are to be preferred. During the boiling of 
liquids the rate of evaporation depends (the source of heat being 
constant) entirely upon the extent of surface to which heat is applied, 
since the more numerous the points of contact of the vessel with the 
source of heat the more rapid must be the formation of vapor, and 
ebullition is but the phenomenon of the rapid disengagement of 
vapor from the interior of a liquid. 

Evaporation in vacuo, being conducted under greatly reduced pres- 
sure, is admirably adapted to the concentration of liquids holding- 
vegetable matter in solution, but is employed only in large manufac- 
turing establishments, owing to the complicated and expensive appa- 
ratus necessarv for the operation ; the process insures rapid evaporation 
at a low temperature, without the possibility of injury from contact 
with the air. In sugar refineries weak saccharine solutions are 
rapidly concentrated in vacuum pans to avoid coloration and inver- 
sion of the sugar. For the preparation of fluid and solid extracts, 
evaporation in a vacuum apparatus offers advantages not obtainable 
by any other method, as a low temperature and complete exclusion of 
air insure the retention of soluble matter in its original form as 
extracted from the drug. The vacuum apparatus consists of an air- 
tight boiler connected with a steam-bath and an air-pump operated 
by machinery, for exhausting the air and vapor. 

Spontaneous evaporation proceeds naturally, without the use of 
external force, and consists in allowing vaporization to take place 
at the ordinary temperature. It is due to diffusion of the vapor 
of the liquid into the surrounding atmosphere, and _ its rapidity 
depends upon the dryness and temperature of the air; the most 
effectual means of promoting it, therefore, is to allow a current of 
warm, dry air to pass over the surface of the evaporating liquid, as 
this will remove the superincumbent air as soon as diffusion into it 
has taken place 

The most desirable evaporating dishes for general use are those 
known as Royal Berlin porcelain ware (see Fig. 149); they resist 

sudden changes in temperature better 
than other earthen vessels, and possess 
the great advantage of not being perme- 
able by colored fluids. When used over 
direct fire, a piece of wire gauze should 
be interposed between the flame and 
Royal Berlin porcelain dish. ^ ^^ g0 M t() distribute the heat 

more uniformly over the bottom of the vessel and prevent the 
flame from striking any particular point. As glass and porcelain 
vessels are liable to crack when suddenly brought in contact with a 
cold surface after having been heated, it will prove economical to 




156 



GENERAL PHARMACY. 



place them on straw rings or rubber grommets (see Figs. 150 and 
151), when hot; these also serve admirably as supports to prevent 



Fig. 150. 



Fig. 151. 





Sraw ring for supporting dishes and flasks. 



Grommets. 



Fig. 152. 



W 



A 



II \o\ n 



tilting of round-bottom dishes and flasks. Grommets are easily 
made by forming rubber tubing into a circle and uniting the ends by 

means of a wooden plug; three short 
pieces of similar tubing of larger size 
are then placed one over the joint and 
the others at equal distances apart, 
which arrangement permits a circula- 
tion of air around the bottom of the 
vessel. Enamelled cast-iron dishes are 
extensively used, but, owing to the 
non- uniform expansion and contrac- 
tion of the metal and enamel, the latter 
is apt to crack and chip off, unless heat 
be very carefully applied; the so- 
called " agate ware" dishes are better, 
being made of sheet- iron and then 
enamelled. For neutral liquids, well- 
tinned copper pans may be employed, 
while for the evaporation of solutions 
of caustic soda or potassa, silver or 
perfectly clean iron vessels are neces- 
sary. 

Evaporation of liquids in open ves- 
sels is materially facilitated by keeping 
the liquid in motion, which, in small 
operations, can be readily done by 
stirring with a glass rod or porcelain 
spatula, and on a large scale by means 
of a mechanical stirrer operated by 
steam or water power. A simple form 
of mechanical stirrer is shown in Fig. 
152 ; it was devised by John Moss, of 
England, and consists of a 1 J inch shaft, A, and a hollow shaft, B, 
which readily slides over it. These shafts are fastened together at C, 



3C 




Moss' mechanical stirrer. 



SEPARATION OF VOLATILE MATTER. 



157 



by means of a pin, and are held vertically over the centre of the evap- 
orating pan by means of the brackets, D, attached to the wall. Power 
for turning the shaft is supplied by a band passing around the 
grooved pulley at E. To the lower end of B is attached a hard-wood 
block, on the opposite sides of which are fastened the stirring paddles, 
F, which can be set at any desired angle, by means of winged-screw 
bolts, as seen in the cut. The paddles, which are usually made of 
ash, may consist of solid blades, 2 feet long by 2J inches wide and 
§ inch thick, but are preferably perforated with holes not less than 1 
inch in diameter, which prevent the contents of the pan from mov- 
ing around as a solid mass, and insure the formation of currents 
of different sizes, moving at different rates of speed, whereby evap- 
oration is greatly facilitated. 

♦ Corrosive vapors are sometimes given off during the evaporation 
of acid liquids ; to prevent these from contaminating the atmos- 
phere of the store or laboratory, and also to avoid saturating the air 
with moisture, evaporation may be conveniently conducted uuder a 
hood commuuicating with a flue. When evaporation is directed to 
be carried to a given weight, a tared dish must be used, the dish and 
contents being weighed from time to time until the desired weight has 
been reached. If evaporation is to be carried to a given volume, the 
simplest plan is to measure the desired volume of water into a dish 
standing on a level surface, then introduce into the centre of the liquid 
a thin stick of wood and mark the height to which the water reaches 
— the liquid to be evaporated must be reduced in this same dish until 
it stands at the point indicated by the notch on the stick. 



Desiccation. 



Desiccation, or exsiccation, a process of drying completely, is 
another method of evaporation, and is employed for driving off the 



Fig. 153. 



Fig. 154. 




Hot-water drying oven. 



Hot-air drying oven. 



158 



GENERAL PHARMACY. 



moisture from vegetable drugs, crystalline salts, precipitates, pills, 
tablets, lozenges, etc. The temperature for effecting desiccation mav 
vary from 40° C. (104° F.) to 200° C. (392° F.), the heating being 
carried on either in the open air on sand-baths or in closed compart- 
ments. For small operations, and when heat not higher than 100° C. 
(212° F.) is required, a portable water-oven (Fig. 153) will answer 
admirably, This consists of a double-walled copper box containing 
water, which may be heated to boiling, and thus heat supplied to the 
interior compartment, which is provided with a perforated tray, a 
closely-fitting door, and an opening in the top for the escape of 
moisture. For temperatures above 100° C. (212° F.) a hot-air bath 
(Fig. 15-1) may be employed. This consists of a single- walled copper 
box through which heated air is constantly circulating, and which is 
provided with a thermometer through an opening in the top. In large 
manufacturing establishments desiccation is carried on in appropriate 
drying closets built of kiln-dried wood and heated by coils of steam pipe. 
The term exsiccation, in pharmacy, is usually reserved for a pro- 
cess of evaporation in which crystalline salts are first moderately 
heated to efflorescence, and then with constant stirring more strongly 
until all water of crystallization has been expelled and the powder has 
ceased losing weight. Dried alum, dried sulphate of iron, and dried 

sulphate of copper are prepared 
by exsiccation. Exsiccated or 
anhydrous salts may be restored 
to their original composition by 
simple solution in water. 

Desiccator is the name applied 
to glass apparatus of varied con- 
struction, in which substances, 
after having been completely 
dried by heat, are allowed to cool 
in air which is kept entirely free 
from moisture by strong sul- 
phuric acid, fused calcium chlor- 
ide or freshly-burned lime, placed 
in the lower cup of the apparatus. 
Sometimes the desiccator is also 
used to abstract moisture from 
material which, owing to its volatile nature, cannot be exposed to 
heat without loss or injury, and since sulphuric acid and lime both 
have a great affinity for water, perfect desiccation can thus be effected. 
Fig. 155 represents one of the styles of this very useful apparatus, 
which is indispensable in quantitative chemical analysis. 



Fig. 155. 




Desiccator. 



Incineration, Calcination, and Torrefaction. 

Incineration, or reduction to ash, is a process of separation applied 
to vegetable matter, which consists in heating it to redness in open 



SEPARATION OF VOLATILE MATTER. 159 

vessels, with full access of air, until all carbon has been consumed, 
or converted into carbon dioxide. 

Calcination differs from incineration chiefly in being applied to 
mineral substances, which are heated to redness without fusion, for 
the purpose of expelling some volatile constituent at a high heat, as 
the carbonic acid from magnesium and calcium carbonates in the 
preparation of magnesia (calcined) and unslaked lime, or the nitric 
acid from mercuric and cupric nitrates in the preparation of the 
respective oxides. 

Torrefaction, or roasting, is not so much a method of separation 
as one which is intended to modify the properties of substances by 
exposing them to dry heat to a point short of carbonization. 
Roasted coffee is probably the most familiar example. Thirty or 
forty years ago physicians used rhubarb, dried, and roasted in very 
coarse powder, which had thus lost its cathartic properties, but had 
retained its astringency. 

Distillation. 

Distillation differs from evaporation chiefly in the utilization of 
the volatilized liquid, and in order, therefore, that no loss may occur, 
the process must be conducted in certain closed apparatus, where the 
condensation of the vaporized liquid may be effected. As the appli- 
cation of heat to a liquid is necessary to convert it into vapor, so, 
inversely, the withdrawal of heat from vapor is essential to reconvert 
it into a liquid, and these two operations constitute the process of 
distillation ; the necessary apparatus, then, must consist of two 
parts, a boiler, or vaporizer, and a condenser, to which may be 
attached a separate receiving vessel. The condensed vapor is called 
the distillate. 

The rationale of the process of distillation may be explained as 
follows : Heat is applied to a liquid in a closed vessel, and is absorbed, 
which causes the liquid to change its state of aggregation to that of 
vapor; the vapor enters the condensing tube, where it comes in con- 
tact with the cold surfaces chilled by water on the outside; immedi- 
ately it begins to part with its latent heat, transferring it to the cold 
surface and the water, and assumes again its original liquid form. 

The temperature of steam not under pressure is 100° C. ('^12° F.), 
in addition to which it carries a latent heat of 550° C. (990° F.); if 
steam is condensed and the distillate collected is to have a tempera- 
ture of 50° C. (122° F.), at least 600° C. (1080° F.) of heat must 
be given off or transferred to the water in the cooler. In other 
words, each liter of water converted into steam requires six liters of 
water at 0° C. (H2° F.) to convert it back into water having a 
temperature of 50° C. (122° F.). 

Alcoholic vapor requires ouly about one- half as much cold water 
for condensation as aqueous vapor,' since its sensible beat is 78. 2° ( '. 
(172.4° F.) and its latent heat only 215° C. (387° F.). The sensi- 



160 



GENERAL PHARMACY. 



ble heat of the vapor of official dilated alcohol is 82° C. (179.6° F.), 
and its latent heat about 260° C. (468° F.). 

As such large quantities of water for condensing purposes are not 
practically available, the same object is attained — the withdrawing of 
the latent heat from vaporized liquids as completely as possible — by a 
continuous supply of cold running water. It has been frequently 
observed in the preparation of distilled water, that more rapid con- 
densation takes place if the water surrounding the condenser be sup- 
plied slowly and thus allowed to become warm. The outlet, or lower 
end of the condensing tube, should always be kept coolest, hence cold 

Fig. 156. 




Simple distillation from a flask. 

Avater must be supplied at this point and carried upward. | Care must 
also be observed that the application of heat and refrigeration be 
properly adjusted, so that vapor be not generated in excess of the 
capacity of the condenser. 

The simplest form of distillatory apparatus consists of a flask, or 
retort, in which the liquid to be distilled is vaporized, and a receiver 

Fig. 157. 




Plain retort with adapter, a, and receiver, b. 



immersed in cold water, in which the vapor is condensed. When a 
flask is used, this is conuected with the receiver by means of glass 
tubing, as shown in Fig. 156, while in the case of the retort, connec- 
tion is made either by means of an adapter, see Fig. 157, or by in- 



SEPABATIOy OF VOLATILE MATTER. 



161 



serting the beak of the retort directly into the receiver, as shown in 



Fig. 158. 



To cool the vapor still more thoroughly, the beak of the retort, or 
the tube connecting the flask with the receiver, may be wrapped in 
part with cotton cloth, upon which a constant stream of cold water 
is allowed to trickle, the water being prevented from running into 
the receiver, by suspending the end of the cloth in the receptacle for 



Fig. 158. 




Fig. 159. 



Tubulated retort and flask receiver. 

waste water. Tubulated retorts have almost entirely superseded the 
plain variety, as they possess the advantage of being more easily 
tilled and cleaned, and also admit of the introduction of a ther- 
mometer or safety-tube, through a cork in the tubulure. A safety- 
tube, Fig. 159, is often necessary in distillation from retorts or flasks, 
to allow the escape of large volumes of vapor 
accumulated and suddenly evolved, which 
otherwise might endanger the apparatus or 
cause the liquid to rise and flow over into 
the condensing tube. Wide-mouth, flat- 
bottom flasks are preferable to retorts, as 
they can be more readily filled, connected 
and cleaned, and are easily supported on a 
sand or water-bath. 

For many purposes, when the most perfect 
refrigeration of vapor possible is desired, the 
apparatus known as the Liebig condenser 
will be found extremely useful, its construc- 
tion being such as to insure a constant supply 
of cold water around the condensing tube, 
which can be readily connected with any 
flask or retort by means of corks and glass 
tubing. Liebig's condenser consists of two 
tubes, one within the other ; the inner always 
of glass, the outer of glass or metal and 
provided with attachments for supply and 
waste of water, which is made to enter near the lower end and to 
traverse the whole length of the outer tube before it is discharged 
at the upper end ; therefore, as the vapor passes downward in the 

11 




Satoty-tube. 



162 



GENERAL PHARMACY 



inner tube it is continually cooled, and thus perfect condensation 
effected before it reaches the. receiving vessel. Fig. 160 shows an 
all-glass Liebig condenser attachable to any filtering stand and capa- 
ble of being set at any angle or height, by means of the clamp 
support, to suit the position of the flask or retort with which it is to 
be connected. 

Fig. 1G0. Fig. 161. 





All-glass Liebig condenser, with adjustable clamp 



Squibb's upright condenser. 



In order to economize space on the laboratory table, Dr. Squibb 
has devised an upright condenser, also made of glass, which can be 
attached, like the preceding one, to a stand ; it is very effective, and 
differs from the Liebig condenser in having the condensing tube 
doubled like a U, as shown in Fig. 161. The outer lines represent 
the water-case tube, v V the vapor tube of U-shape with a small 
opening at the lower end, from which the condensed liquid escapes to 
a proper recipient, while any uncondensed vapor passes to the other 
leg of the tube, is there condensed, and flows downward to the 
outlet. R is the tube supplying cold water to the lower end of the 
water case, which rises and finally flows out through e. 



SEP. 1 11. 1 Tins OF 1 r OLA TILE M. 1 TTER. \ 63 

For large operations, condensation of vapor is usual ly effected in a 
metal or stoneware tube bent in the form of a spiral, and known as a 
condensing worm, see Fig. 162, inclosed in a metal or wooden case, 
which is kept supplied with a constant stream of cold water. On 
account of the difficulty encountered in cleaning the worm, other 
arrangements have been suggested, some of which are extensively 
employed in Europe. Fig. 163 represents the Beindorf condenser, 
in which the vapor is made to pass through three straight tubes, eon- 



FlG. 162. 



Fig. 163. 




Worm condenser. 



The Beindorf condenser. 



necting with a common outlet tube; by unscrewing the upper half of 
the globular chamber into which the vapor first passes, all the tubes can 
be thoroughly cleansed. The Mitscherlich condenser, Fig. 164, dif- 
fers from others in keeping the vapor in contact with two separately 
cooled surfaces, which insures more rapid condensation ; as shown in 
the illustration, the condensing chamber consists of a somewhat ta- 
pering cylindrical vessel, a, ending in a tube, the whole made of metal 
(preferably block-tin), and resting on a support in a large metal or 
wooden case, b ; into this condenser is accurately fitted at the shoulder 
a similar metal cylinder, c, cone-shaped at the closed end. By means 
of long funnel tubes cold water is continually supplied at the bottom 
of the outer and inner coolers, b and c, which rises as it becomes 
warmed, and flows out at the top at d and d; the distillate Hows off 
into a receiver at/. In practice, the Mitscherlich condenser has been 
found very effective, and if the inner cooler has been properly fitted 



164 



GEXERAL PHARMACY. 



Fig. 164. 



to the condensing chamber, no escape of vapor need be feared; it is 
readily taken apart and cleaned, and the only apparent disadvantage 
lies in the double water supply and waste. 

It frequently happens, when distilling from glass flasks or retorts, 
that the liquid, although boiling at first quietly, suddenly begins 
to evolve vapor violently, the phenomenon repeating itself from time 

to time. This outburst of accu- 
mulated vapor is termed bump- 
ing, and although its true cause 
has not yet been satisfactorily 
explained, it is known to occur 
chiefly in smooth glass vessels ; 
it is both annoying aud danger- 
ous, as it may result in fracture 
of the vessel, or in the liquid 
splashing upward into the con- 
densing tube. Bumping may 
be due to unequal heating of the 
vessel, for if the flask or retort 
be covered with a hood of paste- 
board or metal, so that the heat 
be equally diffused, it occurs but 
rarely and less violently. An- 
other remedy consists in intro- 
ducing angular bodies into the 
liquid, such as pieces of pumice- 
stone or glass, or a long plati- 
num spiral, which will afford a 
ready means of escape for the 
vapor from the bottom of the 
liquid. Prof. Proctor, of Eng- 
land, has proposed as a very 
effectual remedy, to pass a slow 
current of air, hydrogen, or car- 
; for small operations this may 
by means of an India-rubber 




The Mitscherlich condenser. 



bon dioxide, through the hot liquid 
be done by forcing a stream of air, 

ball bellows, through a glass tube drawn out to a capillary tube and 
dipping to the bottom of the liquid, while heat is being applied. Ebul- 
lition is said to go on smoothly so long as this is continued, but bump- 
ing will commence as soon as the supply of air ceases. Another plan 
which has been found very satisfactory, especially in the process of 
distillation, is the suction of air through the retort by means of an 
aspirator attached to the receiver. 

For the recovery of alcohol from weak percolates in the concentra- 
tion of vegetable solutions by distillation, special metallic stills have 
been devised. Those made of heavily-tinned copper, of one- to five- 
gallon capacity, will be found most desirable for pharmacists. Figs. 
165, 166, 167, and 168 represent different styles of pharmaceutical 



SEP. 1 RATION OF I 'OLA TILE AT, 1 277:/.'. 



165 



stills in use at the present time. Beck's still (Fig. 16')), designed 
in 1893, is one of the best stills made for the concentration of weak 
percolates and the recovery of alcohol. It is simple in construction, 
efficient iu condensing power, and easily cleaned. It is made of 



Fig. 165. 




Beck's pharmaceutical still. (Exterior view.) 



a ( 




(Interior view.) 



heavily-tinned copper, and the evaporating pan has a capacity of two 
gallons. The cold water, which is made to circulate freely between 
the double walls of the cone-shaped head, is supplied near the base on 
one side, at a, and discharged at the top on the other side, at b. The 
vapor is condensed on the under side of the still-head, the distillate 



166 



GENERAL PHARMACY. 



collecting in two gutters or troughs, one above the other, whence it 
is discharged through a common outlet, c, as shown in Fig. 165. The 
water-bath and condenser are securely clamped together by means of 
six bolts and nuts, the rim of the evaporating pan being interposed 
between two flat rubber rings, and an air-tight joint thus pro- 
duced. A small tube on the side of the water-bath is for the 
escape of steam, and if about one and a half gallons of water be put 
into the bath when the still is started, it will not require refilling for 
about twenty-four hours. If the quantity of liquid to be distilled is 
in excess of the capacity of the. evaporating dish, the latter may be 
refilled by means of a long-stem funnel through the opening in the 
apex of the still-head. The Beck still can be heated with either gas 
or oil, and if water attachments are not convenient, a barrel of cold 
water may be placed at some height above the still, from which the 
condenser can be supplied. 

The special features of the Remington still (Fig. 166), are the 
peculiar shape of the still-head and the construction of the condenser. 
In the former, the opening for the passage of the vapor is drawn over 



Fin. -[GC, 




The Remington still. 



to one side, instead of being in the centre as usual, by which arrange- 
ment the condensing surface of the head is greatly reduced and con- 
densation of vapor within the body of the still obviated as far as 
possible. The condensing tube represents a multiple Liebig con- 
denser, seven block-tin tubes being so arranged within a copper case 
that cold water is constantly circulating between them. Two ground 



SEPARATION OF VOLATILE MATTER 



167 



brass joints are used— one at the point of juncture of the condenser 
with the still-head, the other where the nose-piece is attached to the 



Fig. If. 




The Prentiss alcohol-reclaimer. 



end of the condenser. The capacity of the still is three gallons, and 
by the siphon arrangement shown in Fig. 166 it is possible to feed 
the still from a reservoir while distillation is in progress. 



Fig. 16S. 




latic still. 



The Prentiss Alcohol-reclaimer (Fig. 167) is easily operated. It 
is made of tinned copper, and is provided with an upright column, B, 



168 



GENERAL PHARMACY. 



screwed to the top of the still, in which is placed a rod carrying a 
series of perforated tin disks intended to increase the alcoholic strength 
of the distillate by condensing the aqueous vapor, which then returns 
to the still, while the vapor of alcohol passes on to the condenser 
proper. The vapor passes from the column through a short tube, c, 
to the condenser, which consists of a twelve-ounce copper can, d, 
containing a tube bent zigzag, and supplied with cold water by means 
of a funnel tube, E, reaching to the bottom of the can. The dis- 



FlG. 169. 




100-gallon copper still, with upright condenser. 

tillate is collected at the outlet, G, a continuation of the zigzag con- 
densing tube, while the waste-water flows out at f, which is con- 
nected with the sink by means of rubber tubing. 

The Anderson Automatic Still, Fig. 168, differs from the others 
described, in the continuous automatic supply of water to the water- 
bath. The refrigeration of vapor is effected by a free circulation of 
water between the walls of the cone-shaped condenser, as in the 
Beck still, the distillate collecting in a gutter at the base of the cone. 
The water in the condenser gradually becomes warm and flows into 
the water-bath, which is kept filled to a uniform height by means of 



SEP. 1 11. 1 TION OF 1 VLATILE M. L TTER 



169 



an overflow pipe, and thus the necessity of replenishing the boiler 
with cold water from time to time, in large operations, is obviated. 
The liquid to be distilled is heated in a broad, shallow evaporating 
dish, from which the alcoholic vapors rise rapidly, owing to the large 
extent of surface exposed. 

Automatic stills are recommended and largely used for the distil- 
lation of water, but, when absolute purity is desired, it must not be 
overlooked that, in automatic stills, the air and other gases contained 
in the water are sure to pass out with the steam and redissolve in 
the condensed vapor, so that, while all non-volatile impurities are 



Fig. 170. 




OUTLET 



Large copper still, with worm condenser. 



removed, volatile matter is sure to contaminate the distillate. Dis- 
tilled water entirely free from air and all other impurities can only be 
obtained by rejecting the first portion of the distillate (about 10 per 
cent.), which contains the volatile matter, and allowing the last portion 
(about 10 per cent.) to remain in the still ; this will retain all mineral 
impurities and such decomposition products as may result from the 
prolonged action of heat on organic constituents. Only about 80 per 
cent, of the volume of water to be distilled should be collected and 
considered absolutely pure. The tubes in which the aqueous vapor is 
condensed must be of glass or pure block-tin. 

In the manufacture of fluid and solid extracts and similar prepa- 
rations, on a large scale, stills heat< d by steam are employed for the 
concentration of weak percolates and the recovery of alcohol from 



170 



GENERAL EH ARM A CY. 



the dregs. Such stills are made of heavily-tinned copper, and will 
hold from 50 to 250 gallons of percolate. The boiler, or evaporating 
pan, is partly enclosed in a copper jacket provided with an inlet and 
outlet for steam, by which means heat is supplied to the liquid. Figs. 
169 and 170 represent two large steam stills of different designs. 

Fig. 171. 




Still and condenser designed by Dr. Charles Rice. 



Condensation of the alcoholic vapor is effected by either a worm 
or an upright condenser, the latter usually consisting of a number of 
straight block-tin pipes encased in a copper cylinder, on the princi- 
ple of the Liebig condenser. 



SEPARATION OF VOLATILE MATTER. 171 

The still designed by Dr. Rice (see Fig. 171) presents the pecu- 
liarity of having the condenser situated immediately above the still- 
head, which is for the double purpose of saving floor-space and allow- 
ing the condenser to be used a^ a reflux condenser in the case of 
continuous percolation, as explained below. The case enclosing the. 
condensing coil is made of copper, has a rounded bottom, and is 
closed at the top ; cold water is supplied at the bottom at B by means 
of the rubber tube, a, and is discharged at c, near the top, by means 
of a tube leading to the waste-pipe, d. The small tube near B, 
usually closed with a cork, is for the purpose of emptying the water 
without removing the tube A. The head of the still is provided with 
three short tubular openings, one for refilling the still when required, 
another for inserting a thermometer, and the third, shown in the cut, 
for carrying a safety tube, L. The vapor-pipe starts from the still- 
head at E, and is connected with the projecting end of the block-tin 
condensing coil, near the upper part of the tank, at e. The worm 
inside of the coudenser tank has a uniform downward descent, and 
emerges at F, extending a short distance to the joint, by means 
of which it is connected with a block-tin pipe, j, leading to the 
receiving vessel. The head is attached to the body of the still 
by means of a rubber washer and iron clamps, and can be readily 
removed, after taking off the clamps, by attaching the tackle, K, to 
the top of the condenser and hoisting the whole upward. Steam is 
admitted to the jacket at M, and x is the exhaust pipe for the same. 
About the middle of the lower projecting end of the condensing tube 
a branch passes dowmward back to the still at g, and terminates under 
the head, in the form of an ^O , which trap prevents any condensed 
liquid from flowing back into the still should the stopcock at H be 
open. The object of this branch pipe is to carry the condensed alco- 
hol back to the still when the apparatus is used for continuous perco- 
lation of such substances as mix vomica, aconite, etc. When the still 
is to be used for this purpose, a large tin-lined copper percolator, into 
which the moistened drug has been packed and covered with a felt 
diaphragm, is securely clamped between the head and body of the still, 
into which menstruum has previously been poured. When steam is 
admitted to the jacket the alcohol is vaporized, recondensed in the con- 
denser above, and made to flow back to the still and on to the drug in 
the percolator by means of the branch pipe and stopcock at H, the tube, 
J, having been disconnected and the joint closed with a cork. The 
percolate collects in the body of the still and the alcohol is again 
vaporized as before, the process continuing at the pleasure of the 
operator, and the drug bein^ thoroughly exhausted with a minimum 
quantity of menstruum. Thus, prolonged digestion and continuous 
percolation of large quantities of drugs can be successfully carried on 
in this apparatus without any loss of alcohol. 

The so-called dreg stills for the recovery of alcohol from the marc 
are sometimes made of 300 or 500 gallons capacity, of heavy copper, 
but not jacketed ; as no injury can be done to the exhausted 



172 GENERAL PHARMACY. 

material by heat, live steam is passed directly into the still-body 
containing the marc, and the alcohol is thus rapidly vaporized and 
forced into suitable condensers. 

Vacuum stills are uecessarily of a somewhat different construction, 
and, as already stated on page 151, are only used in large manu- 
facturing establish ments, where the concentration of bulky vegetable 
solutions, at low temperatures, is frequently desired. Without the 
use of vacuum apparatus, the evaporation of solid extracts, without 
injury, to a condition suitable for powdering, would be an impossi- 
bility. Fig. 172 represents a large vacuum still in operation at the 
establishment of Sharp & Dohrne, of this city, to whose courtesy I 
am indebted for the privilege of giving a photographic reproduction 
of the apparatus. The still proper consists of an egg-shaped vessel 
of heavy tinned copper, partly encased in a jacket, to which steam is 
supplied ; it is provided with a vacuum gauge, thermometer, sight- 
glasses through which the process of evaporation may be watched, 
and an ingenious stirring apparatus attached to the vertical shaft, 
operated by means of the two geared wheels seen above the still. 
The liquid to be evaporated is supplied automatically through the 
tube seen projecting from the side of the still, to the right of the 
wheel which operates the clamp holding the man-hole cover in posi- 
tion. Cleaning: of the still is effected through a large man-hole in 
the lower front of the still-body. The vapor of the evaporating 
liquid passes through the large tube projecting laterally from the 
still-head, into a series of condensing tubes resting in a large iron 
tank provided with a constant supply of water; any vapor escaping 
condensation in these tubes, which may happen on account of its more 
rapid movement caused by the action of the vacuum pump, will be 
caught and condensed in the Liebig condenser situated diagonally 
underneath the iron tank. The distillate is finally discharged 
through the large spout which may be seen emerging from the valve 
box connected with the pump about the centre of the lower part of 
the figure. 

The rarefication of air in the apparatus is accomplished by means 
of an exhaust pump situated under the condensing tank and com- 
municating with the condensing tubes. 

When the still is to be operated, the pump is started, exhausting 
the air from the still until the desired vacuum is reached, as indi- 
cated by the barometric gauge attached to the wall between the still 
and the condensing tank, and connected with the still by means of a 
two-neck bottle and a block-tin pipe. A rubber hose dipping into 
the liquid to be evaporated is then connected with the projecting 
tube to the right of the man-hole, and the stopcock in the tube 
having been opened, the liquid is allowed to flow into the still by 
atmospheric pressure until it reaches the desired height in the still, 
after which the stopcock is partially closed and so set that the sup- 
ply of liquid is automatically kept up in proportion to its evapora- 
tion — the aim being to preserve, as far as possible, the original volume 



S ER lli. 1 TION OF \ 'OLATIL E M. I TTER. 



173 



of the liquid in the still. By this arrangement, large volumes of 
percolate can be concentrated in a comparatively short time, without 
taking the still apart or interfering in any way with the distilla- 



FiG. 172. 




Large vacuum still and condensing tank. 



tion of the menstruum. Evaporation taking place at a low tempera- 
ture and with entire exclusion of air, no possible injury can occur to 
the constituents in solution. 



174 GENERAL PHARMA CY. 

Fractional distillation is the name applied to a process intended to 
separate liquids of different boiling-points, and is often a valuable aid 
in determining the composition of a mixture, or in the purification 
of certain chemicals. It necessitates the introduction of an accurate 
thermometer into the retort, flask, or still, so that a change in the 
boiling-point may be promptly observed and the receiving flask 
changed accordingly. As all liquids will begin to vaporize before 
their boiling-point is reached, perfect separation is impossible in a 
single operation; it is, therefore, customary to collect the liquids con- 
densed during a certain range of temperature in the still, and to sub- 
ject these again to the same process of fractionation, until finally a 
pure liquid showing a stationary boiling-point is obtained. As an 
example, may be cited a mixture of ether, chloroform and alcohol. 
If pure, the three liquids will boil at 37° C, 60.5° C, and 78° C. 
respectively ; but a mixture may possibly boil at about 40°, when 
all of the ether will distil over, together with small portions of chloro- 
form and traces of alcohol. As the temperature rises to 65° C, the 
distillate will consist of chloroform mixed with small portions of 
alcohol; and finally, at 78° C, alcohol alone will distil over. By 
changing the receiving flask at 40° C. and 6o° C, fractions will be 
obtained entirely different in composition from the original. If the 
first fraction be now distilled, the liquid will probably boil near 
38° C, and by carefully watching the thermometer and changing the 
receiver, ether almost entirely free from chloroform and alcohol may 
be obtained. By thus carefully collecting the fractions at fixed 
temperatures and re-distilling each by itself, more thorough separa- 
tion is possible. 

During the ebullition of a pure liquid no change of temperature 
will be indicated by the thermometer, but in a mixture of inter-soluble 
liquids, a gradual rise will continue as the more volatile are vapor- 
ized, this rise being slow or rapid as either the more volatile or less 
volatile liquids predominate. If a mixture of only partly miscible 
liquids be subjected to distillation, the temperature will remain sta- 
tionary during the ebullition of the more volatile liquid and only 
begin to rise when the same has nearly all been vaporized. In such 
cases almost perfect separation can be effected, particularly if the 
boiling-points of the liquids lie far apart. Examples : benzin and 
alcohol, or alcohol and oil of turpentine. Numerous coal-tar pro- 
ducts are obtained by fractional distillation. 

Fractional condensation is closely allied to fractional distillation, 
and is largely employed in the rectification of alcohol and the purifi- 
cation and concentration of glycerin and other liquids. It is 
effected by passing the mixed vapors into a series of condensers kept 
at regular temperatures, each succeeding one being cooler than the 
one which precedes it. 

Destructive distillation is the process of heating dry vegetable or 
animal matter, in suitable closed vessels, until everything volatile has 
been expelled and a fixed residue is left. As the name indicates, the 



SEPARATION OF VOLA TILE M. 1 TTEB. 175 

process involves the destruction of the original compound, whereby 
products of simpler composition arc obtained. In order to avoid oxida- 
tion, destructive distillation must he carried on in closed apparatus 
with entire exclusion of air, and as the heat necessary is in most cases 
far greater than that to which glass vessels could be safely exposed, 
iron retorts or cylinders are employed. The residue left in the iron 
retort is often a fused mass insoluble in water, which necessitates 
mechanical means for its removal. The products of destructive 
distillation, in their crude state, are usually accompanied by a peculiar 
smoky odor called empyreuma, said to be due to an oil developed 
during the process of decomposition ; this is subsequently removed by 
rectification. The most striking examples of destructive distillation 
are the manufacture of acetic acid from wood and of illuminating 
gas from coal. 

Sublimation. 

Sublimation is the term applied to the process of vaporizing vola- 
tile solids and condensing the vapor back into a solid ; it must not 
be confounded with the term dry distillation, which is frequently 
used in place of destructive distillation. The product of sublima- 
tion is known as a sublimate, and may occur either in the form of a 
tine powder or compact masses. 

The object of the process of sublimation may be the purification 
of a substance by separating the volatile solid from less volatile or 
fixed impurities, as in the case of sulphur, camphor, naphtalene, and 
iodine, or the separation and collection of volatile solids resulting 
from chemical reaction at higher temperatures, as in the case of 
pyrogallol, calomel, and mercuric chloride. 

The apparatus consists of a subliming vessel made of iron, glass, 
or earthenware, and a condenser adapted to the volatility of the pro- 
duct, the condensing surface being kept sufficiently near the source of 
heat to avoid cooling of the vapor before it reaches the condenser. 
If the temperature of the condenser is but little below that of the 
subliming vessel, the vapors of the volatilized substance will not con- 
dense until they strike the surface of the condenser, and will form 
in compact masses, frequently in crystalline condition ; as for instance, 
arsenous acid, corrosive mercuric chloride, ammonium carbonate, and 
commercial sal-ammoniac. In order to obtain the sublimate in the 
form of powder, the air in the condenser must be decidedly cooler 
than the temperature at which the substance volatilizes, because then 
the vapor will be immediately cooled and rapidly deposited in very 
small particles, as in the case of calomel, sulphur, and camphor 
when intended for subsequent compression. 

The process of sublimation is confined to the larger operations of 
the manufacturing chemists, but can be demonstrated in a small way 
by placing a few grains of camphor or iodine in a long test-tube and 
then heating until all has been volatilized ; in a few minutes the 
substance may be gathered in the form of very small crystals from 
the upper part of the tube. 



CHAPTEE XI. 



CRYSTALLIZATION. 



Fig. 173. 



TV 



The subject of crystallization, while a most important branch of 
mineralogy and chemical physics, is of less value in pharmacy 
proper; but, as the Pharmacopoeia makes frequent use of terms be- 
longing to the study of crystallology, and as the pharmacist may have 
occasion to resort to crystallization for the purpose of determining 
the character and quality of substances, a short notice is deemed 
desirable. 

Crystallization may be looked upon as another method of separa- 
tion, as it is frequently employed for the purpose of removing 

impurities from crystallizable sub- 
stances. The term crystal is ap- 
plied to solid inanimate bodies of 
regular internal structure and defi- 
nite geometrical form, bounded by 
plane surfaces and having angles 
of fixed and constant values. The 
assumption of such distinctive geo- 
metrical forms occurs, as a rule, 
during the change taking place in 
the state of aggregation of sub-" 
stances from the gaseous or liquid 
to the solid condition ; in a few 
cases it occurs also in solid bodies, 
as iron and brass wire. 
In the preliminary study of crystallography, the meaning of the 
following terms must be considered. 

Faces are the plane surfaces bouudiug the crystal (see abdc, efhg,. 
abfe and bfhd, Fig. 173). 

Edges are the lines of intersection of two adjoining faces (see ef, 
ab, fh, bf t db, eg, ea, gh, gf, cd, ea, eg, etc.. Fig. 173). 

Angles are the points formed by intersection of three or more 
faces (see Fig. 173), e, formed by abef, eacg, and efhg ; f, formed 
by bdhf, baef, and efgh; c, formed by dhgc, abdc, and aegc, etc. 
Axes are imaginary lines drawn through the centre of the crys- 
tal, around which the symmetrical deposit of matter has occurred 
during the formation of the crystal (see ik, Im, and no, Fig. 173). 

Amorphous (without form) designates the absence of crystalline 
form and structure, as in acacia, starch, gelatin, etc. 

Di- or tri-morphous (of two or three forms), indicates that the sub- 



in 



a 



CRYSTALLIZATION. 177 

stance occurs in two or three distinct crystalline forms, as carbon, 
sulphur, etc. 

Polymorphous means of many forms. 

Isomorphous (of the same form) indicates that two or more sub- 
stances to which the term is applied, crystallize in the same form; 
thus the chlorides, iodides, and bromides of sodium and potassium 
are isomorphous. Isomorphous bodies are known to resemble each 
other also in chemical composition, and to permit of a ready inter- 
change of constituents, as in the case of the various alums. 

Cleavage is the tendency of most crystals to split in particular 
directions, affording usually even and frequently polished surfaces, the 
direction being always parallel with the planes of the axes, or with 
others diagonal to these. While some crystals cleave very easily, in 
others this tendency is scarcely discernible. 

Tabular crystals are such as crystallize in flat plates, as potassium 
chlorate, iodine, strontium iodide, etc. 

Laminar crystals are such as crystallize in thin plates, as acet- 
anilid, naphtol, calcium hypophosphite, etc. 

Acicular crystals are such as occur needle-shaped, as aloin, cin- 
chonidine sulphate, quinine salts, etc. 

Prismatic crystals are such as resemble a prism, being extended 
chiefly in the direction of the longest axis, as salicylic acid, san- 
tonin, cinchonine sulphate, etc. 

Orthometric refers to the measurement of the angles, and is used 
to siguifv that the three axes intersect each other at right angles. 

Clinometric refers to the intersection of the axes at oblique angles. 

Holohedral, applied to crystalline forms, signifies that the full num- 
ber of faces required by perfect symmetry are present, 

Hemihedral signifies that only one-half the number of faces re- 
quired by full symmetry are present. 

Crystals are formed according to fixed laws of Nature, and there 
can be no doubt that the force of cohesion plays an important part 
in their formation; but no one knows how, or why, the molecular 
particles of certain substances arrange themselves into symmetrical 
deposits, around a common centre, in a manner to give rise to 
numerous distinct and definite forms. 

The large variety of forms in which crystals appear, depends en- 
tirely upon the number and length of the axes and their relative 
inclination — that is, the angles at which they intersect each other. 
All crystalline forms have been reduced by scientists to two main 
groups, the orthometric and the clinometric groups (see above), and 
these have again been subdivided into six systems; the orthometric 
group comprises the regular, quadratic, rhombic and hexagonal sys- 
tems; the clinometric group, the monoclinic and triclinic systems. A.8 
all crystals belong to one or the other of these system^, the salient 
features of each should be studied. 

1. The Ber/ular System, also known as the Monometric, Cubic, 
Octohedral, or Tessular System. 

12 



178 



GENERAL PHARMACY. 



Crystals of this system have three axes of equal length, which 
intersect each other at right angles, as shown in Fig. 174. 

The fundamental forms of this system are the cube and the octo- 
hedron, Figs. 175 and 176. 




Fig. 175. 




Axes of the regular system. 



The cube. 



Alum, phosphorus, arsenic trioxide, diamonds, alkali iodides, 
chlorides, fluorides and cyanides, as well as many metals and their 
sulphides, crystallize in this system. 

2. The Quadratic System, also knowu as the Dimetric, Square 
Prismatic, or Tetragonal System. 



Fig. 17 




Fig. 177. 




Regular octohedron. 



Axes of the quadratic system. 



Crystals of this system have three axes intersecting each other at 
right augles, two of which are of equal length, and one either longer 
or shorter than the other two ; the two equal axes are called 
secondary axes, while the third is termed the primary axis. See 
Fig. 177. 

The fundamental forms of this system are the quadratic octo- 



CRYSTALLIZATION. 



179 



hedroD (also called square-based double pyramid) and the right- 
square prism, Figs. 178 and 179. The pyramids of this system 
have square bases. 



Fig. ITS. 



Fig. n 




Quadratic octohedron. 



Right square or quadratic prism. 



Among the modified forms are the truncated quadratic octohedron. 
Fig. 180, and the quadratic pyramidal prism, Fig. 181. 



Fig. 180. 



Fig. 181. 






Truncated quadratic octohedron. 



Quadratic prism with pyramidal ends. 



Potassium ferrocyanide, calomel, nickel sulphate, boron, tin, 
stannic oxide, magnesium sulphate, zinc sulphate, etc., crystallize in 
this system. 

3. The Rhombic System, also known as the Trimetric or Eight 
Prismatic System. 



180 



GENERAL PHARMACY. 




Fig. 183. 



Crystals of this system have three unequal axes intersecting each 
other at right angles, shown in Fig. 182. The fundamental form of 
this system is the rhombic octohedron or 
right rhombic double pyramid. See Fig. 
183. A modified form is the rhombic 
six-sided prismatic pyramid, Fig. 184. 

Potassium sulphate and nitrate, resorcin, 
zinc sulphate, citric acid, iodine, rochelle 
salt, mercuric chloride, barium chloride, 
tartar emetic, codeine, salicylic acid, 




Axes of the rhombic system. 



Rhombic octohedron. 



pi peri n, Epsom salt, silver nitrate, ammonium sulphate, cream of 
tartar, etc., crystallize in this state. 

4. The Hexagonal or Rhombohedral System. Crystals of this 
system have four axes, three of which are of equal length and are 
called secondary axes, whilst the fourth, known as the primary axis, 



Fig. 184. 





Rhombic prism. 



Axes of the hexagonal system. 



is either longer or shorter than the other three. The primary axis is 
at right angles to the plane of the secondary axes, which intersect 
each other at acute angles. See Fig. 185. 

The fundamental form is the double six-sided pyramid, Fig. 186. 



CRYSTALLIZATION. 



181 



The rhombohedron, Fig. 187, and the regular six-sided prism, Fig. 
188, are modifications of this system. 



Fig 


.186. 




vv 




\ v v\ 




\ ^\ 


/ ...-/•""* 


..\^\^ 


\^^/^^r 









Fig. 1ST. 




Double six-sided pyramid. 



Rhombohedron. 



Sodium nitrate, camphor, graphite, ammonium chloride, ice, calc- 
spar, thymol, metallic bismuth and antimony, arsenic, silicic acid, 
etc., crystallize in this system. 

5. The 31onoclinic System, also known as the Monosym metric, 
Clinorhombic or Oblique Prismatic System. 



Fig. 188. 



Fig. 189. 



Fig. 190. 




Six-sided prism. 



Axes of the monoclinic system. Monoclinic double pyramid. 



Crystals of this system have three unequal axes, two being obliquely 
inclined to each other, the other axis forming right angles with these 
two. See Fig. 189. 

The fundamental forms of this system are the monoclinic double 
pyramid or octohedron, Fig. 190, and the monoclinic prism, Fig. 191. 

Ferrous sulphate, borax, lead acetate, cupric acetate, tartaric acid, 
potassium chlorate and sodium acetate, sulphate, thiosulphate, phos- 
phate and carbonate, crystallize in this system. 

6. The Triclinic System, also known as the Asymmetric, Clino- 
rhombohedral, or Doubly Oblique Prismatic System. 



182 



GENERAL PHARMACY. 



This is the least regular of all the systems, the crystals having 
unequal axes, all obliquely inclined to one another. See Fig. 192. 



Fig. 191. 



Fig. 192. 





Monoclinic prism. 



Axes of the triclinic system. 



The fuudameutal forms of this system are the triclinic prism, 
Fig. 193, and the triclinic octohedron, Fig. 194. 



Fig. 193. 



Fig. 194. 





Triclinic prism. 

Cupric sulphate, potassium dichro- 
mate, gypsum, boric acid, mauganous 
sulphate, etc., cystallize in this system. 

The pyramidal form of crystals is 
found in all the systems above de- 
scribed, while the Cube is Confined to Triclinic pyramid. 

the regular system, and prisms are met 

in all but the regular system. The proper classification of a crystal 
may be determined by measurement of the angles and subsequent 
galculation of the length and inclination of the axes ; the instru- 
ment used for this purpose is known as a goniometer. 

Various methods are employed for obtaining crystals, dependent 
upon the nature of the substance to be crystallized : thus, by sub- 
limation ; by deposition from supersaturated solutions as they cool ; 
by deposition from solutions during slow evaporation of the solvent ; 
by precipitation ; by fusion and partial cooling ; by the action of a 
galvanic current upon a solution ; and by the addition of a substance 
having a strong affinity for the solvent, thereby withdrawing it 
from the solution. The method generally followed is the gradual 
separation from supersaturated solutions as they cool ; if a solution 



CM YSTALLIZA TIOK \ 83 

of saline matter made with aid of heat is allowed to cool slowly, the 
water will gradually evaporate, and in some cases a part of it will 
unite intimately with the soluble substance to form crystals. Water 
which is thus appropriated, and which is essential to the constitu- 
tion of the crystals, is called water of crystallization ; it varies greatly 
for different substances, ranging from 5 to 60 per cent, of the weight 
of the crystals. Crystalline bodies in which this water is entirely 
absent are said to be anhydrous. Some salts combine with various 
proportions of water of crystallization according to the temperature 
at which crystallization takes place, the crystals assuming different 
forms according to the amount of water taken up ; sodium carbonate, 
sodium phosphate, and zinc sulphate, are examples of this class. 

Some crystals will part with a portion of their water of crystal- 
lization w r hen exposed to the air, particularly if the latter is slightly 
warm ; they gradually lose their transparency and the surface be- 
comes opaque from a deposit of dry powder. This change is termed 
efflorescence, and is frequently observed in Epsom salt, sodium car- 
bonate, and borax. Other crystals are inclined to absorb moisture 
from the atmosphere, and in some instances even to such an extent as 
to liquefy ; the terms hygroscopic and deliquescent are used to designate 
this peculiar property, the latter applying to the more aggravated 
form. Potassium hypophosphite, zinc chloride and iodide, potassium 
acetate and carbonate, and lithium bromide, are examples of deliques- 
cent crystals. As a rule, crystals containing water of crystallization 
do not absorb moisture from the air, although calcium chloride, 
potassium citrate, and sodium hypophosphite are marked exceptions. 

Besides the water needed for crystallization, some is also at times 
mechanically retained within the crystal during the formation of the 
latter, and is violently expelled upon application of heat ; such water 
is called interstitial water, because it fills small interstices or spaces 
in the crystal, and water of decrepitation, because it causes the crys- 
tals to decrepitate or crackle when heated, due to slight explosions 
caused by the escape of aqueous vapor from a confined space. It is 
impossible to crystallize all of the substance held in solution, by a 
single operation — a portion will remain in solution in some of the 
water, and this liquid constitutes the mother-liquor, which also retains 
the more soluble impurities. By further concentration the mother- 
liquor can be made to yield fresh crops of crystals. 

The time necessary to complete crystallization will vary with the 
nature of the dissolved body ; the end may be assumed to have been 
reached when the solution has attained the temperature of the sur- 
rounding atmosphere, and the time for this must vary, since the dis- 
solved body, by again taking on the solid form, is continually giving 
out latent heat to the surrounding solution, and thus the actual cool- 
ing is retarded. For small quantities and not very soluble substances, 
twenty-four to thirty- six hours should be allowed, while large volumes 
of solution of readily soluble matter will require from three to six or 
eight days. 



184 GENERAL PHARMACY. 

In order to obtain large and well-formed crystals the solution 
should not be made too concentrated, and should be carefully filtered 
to obtain a perfectly clear liquid, which should be allowed to remain 
undisturbed and protected against dust, in a moderate temperature ; 
it is the very slow evaporation of the solvent that enables the par- 
ticles of dissolved matter to arrange themselves harmoniously and 
symmetrically around the centre of the crystal forming. Perfect rest 
is equally essential, as agitation of the crystallizing solution tends 
to disturb the gradual uniform deposit and causes the formation of 
small and imperfect crystals, as in the case of commercial magnesium 
sulphate, zinc sulphate, etc. 

The proper degree of concentration of the solution must be de- 
termined by the solubility of the substance to be crystallized. If the 
substauce is only moderately soluble, the solution may be evaporated 
until a crystalline crust or pellicle begins to form on the top of the 
liquid ; but in the case of very soluble substances such a degree of 
concentration would be too great, and a better plan is to evaporate 
the solution until a small portion transferred to a glass plate crystal- 
lizes within a reasonable length of time. In large operations, the 
manufacturer relies upon the density of the solution as indicated by 
the hydrometer, and evaporation is continued to such a point as 
experience has taught to be most desirable for perfect crystallization. 

The vessels best adapted for crystallization are deep rough-glazed 
stoneware basins, called crystal lizers, frequently arranged with a lip 
to facilitate the decautation of the mother-liquor ; wooden vats are 
also extensively employed by manufacturing chemists, and in some 
cases these are lined with lead. For very small operations, glass or 
porcelain dishes may be employed, but their smooth surface is not 
favorable to the deposit of crystals. 

Crystallization is often facilitated by placing insoluble foreign 
substances in the solution, which form starting-points or nuclei for 
the process, and to which the crystallizing substance readily attaches 
itself; pieces of string, wire, wood, etc., may be used for the pur- 
pose. Sugar is thus crystallized in the form of rock-candy, by 
stretching strings transversely across the boxes and tubs into which 
the syrup is poured. 

Since crystals do not increase in size from within, as do animals and 
plants, but grow from without, by deposition of solid matter upon 
their surface, it is possible to procure large and well-formed crystals, 
for specimen purposes, by suspending a crystal in a saturated solution 
of its own constituent matter. This proceeding may be termed 
nursing a crystal. Isomorphous crystals are capable of growing in 
each other's solution ; hence if a crystal of potassium alum be sus- 
pended in a solution of ferric alum or chrome alum, the latter will be 
found uniformly deposited, and thus a complete envelope of chrome 
or ferric alum will grow on the original crystal of potassium alum. 



CHAPTER XII. 

CLASSIFICATION OF NATURAL PRODUCTS USED IN 
PHARMACY. 

Plants, either spontaneously or after due subjeetion to various 
processes, yield certain vegetable substances which are extensively 
employed in pharmacy, and which, owing to their different behavior 
as to composition, solubility, etc., have been divided into distinct 
classes, thus : gums, resius, oleoresins, gum-resins, balsams, fats, essen- 
tial oils, etc. Unfortunately the names which from long usage have 
been applied to some drugs are not in all cases indicative of their 
true nature ; hence a knowledge of the characteristics of each class of 
plant products is essential to guard against errors in nomenclature, 
which are of daily occurrence in commercial transactions; for in- 
stance, the names balsam of fir and balsam copaiba are applied to 
substances belonging to the class of oleoresins, and not containing 
any of the principles which characterize the balsams ; gum guaiac 
and gum mastiche are pure resins ; gum benzoin belongs to the class 
of balsams, and gum opium is an inspissated juice of complex com- 
position. 

True gums are amorphous exudations wholly soluble in cold water, 
which are not affected by iodine, but are precipitated by alcohol and 
solution of lead subacetate, the latter being a most delicate reagent 
for the presence of gums. Neutral or normal lead acetate is readily 
miscible with solutions of the true gums, of which acacia may be 
taken as a type. A class of substances formerly called gums are now 
more appropriately known as mucilages, because they differ in several 
respects from the true gums ; they are not completely soluble in 
water (cold or hot), but absorb the same, and in some instances swell 
to a gelatinoid mass. Mucilages are frequently mixed with starch, 
which is easily detected by the blue color produced upon addition of 
iodine solution. Tragacanth and the gummy constituents of flax- 
seed, elm bark, quince seed, etc., belong to the class of mucilages. 

Resins are secretory products, in some instances the result of 
oxidation of volatile oils, and are widely diffused in the vegetable 
kingdom ; they are wholly insoluble in water, except in the presence 
of caustic alkalies, but are readily soluble in alcohol, ether, and 
chloroform, and frequently in fixed and volatile oils. Resins are 
mostly solid and brittle at ordinary temperatures, generally amor- 
phous, readily fusible and inflammable, become negatively electric 
by friction, decompose before volatilizing, and are precipitated from 
their solutions by water and acids. Pine resin, mastiche, jalap resin, 



186 GENERAL PHARMACY. 

and gnaiac resin, are examples of this valuable class of plant pro- 
duets. 

Oleoresins occupy a position intermediate between resins proper 
and volatile oils, and partake of the properties of both classes ; their 
existence confirms the view held as to the formation of some resins in 
plants, and their consistence varies with the relative proportions of 
resin and volatile oil. Like the resins proper, oleoresins are insolu- 
ble in water, but soluble in alcohol and ether ; they possess a marked 
odor, due to the volatile oil present, which latter can be separated by 
distillation, leaving the resin as a solid residue. White turpentine 
is an example of solid oleoresins, and copaiba of liquid oleoresins. 

Glum-resins exist in plants in the form of an adhesive milky juice 
composed of variable mixtures of resin and gum suspended in water; 
they are obtained as exudations, by wounding the stem or root of the 
plant aud allowing the juice to dry spontaneously. The proportion 
of gum and resin varies considerably, not only for different gum- 
resins, but also for different samples of the same gum-resin, and those 
lots are most valuable which contain the largest amount of resin. 
The activity of the drug resides wholly in the resin, and this fact is 
taken into consideration in the official formulas for the tinctures of 
asafetida and myrrh. A peculiarity of all gum-resins is that when 
properly triturated with water they yield milk-like mixtures termed 
emulsions, which fact is due to the suspension of very finely divided 
resin in the solution of gum; these milk-like mixtures cannot be 
obtained if the commercial finely powdered gum-resins be triturated 
with water, but require the use of the natural product in coarse pow- 
der. As prominent gum-resins may be mentioned asafetida, myrrh, 
scammony, and ammoniac. 

Balsams are either resinous or oleoresiuous secretions containing 
benzoic or cinnamic acid, or both ; it is the presence of these acids 
which distinguishes the balsams from ordinary resins and oleoresins. 
Balsams are soluble in alcohol, ether, or chloroform, but insoluble in 
water, although the balsamic principles can be extracted by sublima- 
tion or by treatment with hot water. Benzoin and balsam of tolu 
are examples of resinous balsams, whilst storax and balsam of Peru 
belong to the oleoresinous variety. 

Fats and Fixed Oils. 

The fats used in pharmacy are derived from the vegetable as well 
as the animal kingdom, and are divided into fats proper and fatty 
oils, the latter being known in pharmacy more particularly as fixed 
oils ; when strictly pure they are, as a rule, colorless, odorless, and 
tasteless. True fats are strictly chemical compounds of glycerin and 
fatty acids, and are known as olein, palmitin, and stearin, the former 
being liquid, while the two latter are solid. In fatty oils, olein pre- 
dominates ; while in solid fats, palmitin and stearin are present in 
greater proportions. Fixed oils, as a rule, are liquid at ordinary 



CLASSIFICATION OF NATURAL PRODUCTS. 187 

temperature, while fats proper are of a soft consistence and mostly 
yield liquid fats when subjected to a gradually increased pressure ; 
those of a firmer consistence are usually termed tallows or suets, and 
such as are brittle at common temperatures are known as waxes, 
but these are not true fats. The origin of fixed oils in plants is sup- 
posed to be the starch, while in animal fats they are more probably 
derived from albuminous matter. Fats are lighter than water, and 
insoluble in that liquid ; sparingly soluble in cold alcohol, with one 
or two exceptions ; but, as a rule, freely soluble in ether, chloroform, 
petroleum benzin, carbon disulphide, benzene, etc. ; a hot alcoholic 
solution of fats, in most instances, will deposit them in a crystalline 
condition upon cooling. All fats, whether liquid or solid, appear 
greasy to the touch, and when dropped upon paper produce a stain 
which cannot be dissipated by heat; they have boiling-points vary- 
ing from 260° to 300° C. (500° to 572°' F.), and frequently, when 
thus heated, undergo decomposition and give off acrid irritating 
vapors. Fixed oils usually have a specific gravity of from 0.900 to 
0.930 at 15° C. (59° F.), though occasionally it runs as high as 0.970, 
as in the case of castor oil ; many oils do not congeal until the tem- 
perature has fallen considerably below 0° C. (32° F.), while others 
deposit solid matter at 10° C. (50° F.). Like water, fixed oils 
expand upon congealing, and have been known to burst the vessels 
containing them. Fats are not inflammable, but will burn more or 
less readily by the aid of a wick. Xearly all vegetable and animal 
fats consist of a mixture of two or more fats, and when exposed to 
the air become oxidized, many of them gradually assuming a dis- 
agreeable odor, due to the liberation of odorous fatty acids ; this 
condition is known as rancidity, and may be avoided by keeping the 
fats as free from moisture as possible, in air-tight containers stored 
in a dry, cool, and dark place. Rancid fats may be improved and, 
to a certain extent, restored, by washing them with warm water, or 
by treating them with magnesia or other weak alkali, and afterward 
washing them well. During the oxidation of fats by exposure to 
air, heat is always developed, and certain fabrics, such as woollen 
and cotton rags, which are known to be poor conductors of heat, are 
liable to spontaneous ignition if saturated with fats and exposed to 
the air for some time. Fixed oils may be conveniently divided into 
drying and non-drying oils ; the former upon exposure to air gradu- 
ally thicken, and if in thiu layers, form varnish-like masses, whereas 
the non-drying oils remain fluid and become rancid. 

Although fats are found in various parts of plants, those intended 
for use are collected exclusively from the fruit and seed, and are 
obtained either by expression or by extraction with some suitable 
solvent ; the former process yields somewhat lower results, but is 
preferred because less troublesome and productive in many cases of a 
superior article. In Fig. 195 is shown an hydraulic press extensively 
used for the expression of mustard, cotton seed, and linseed oils. 
The crushed material, after being heated somewhat, is placed in sacks 



188 



GENERAL PHARMACY 



or press-cloths between the series of plates, and pressure applied 
from below, the oil being collected in the large box or trough, and 
from there delivered into the receiving vessel. The residue from 
certain seed expressions is used, under the name of oil-cake, as food 
for cattle and hogs or for fertilizing purposes. Cold expression 



Fig. 19c 




Steam press for fixed oils. 



yields a finer oil than when heat is employed, although slight warm- 
ing is generally resorted to so as to render the oil more fluid in the 
seed and thus insure a better flow. Expressed oils are always more 
or less contaminated with impurities, such as mucilaginous and albu- 
minous matter, which are removed by allowing the oil to settle in 
large tanks and drawing off the clear liquid. Frequently filtration 
is employed for improving the quality of the oil, felt or flannel bags 



CLASSIFICATION OF NATURAL PRODUCTS. 189 

being best adapted for this purpose. When purification of fixed oils 
becomes necessary they are treated either with sulphuric acid, caustic 
alkalies, zinc chloride, tannin, or alkali carbonates, and subsequently 
washed with hot water, after which they are carefully decanted. 

The extraction of fixed oils is conducted in specially constructed 
extractors, frequently so arranged that the solvent is made to act 
upon successive portions of crushed seed, the saturated solution of 
fat being then transferred to a suitable distillatory apparatus, where 
the solvent is recovered, to be again used for subsequent operations. 
The solvents usually employed are petroleum benzin of low boiling- 
point and carbon disulphide ; the oil is obtained in larger quantity 
than by expression, and is free from many impurities often found in 
expressed oils. 

Fixed oils are frequently subjected to a bleaching process, which 
consists in treating the oil with solution of hydrogen dioxide, potas- 
sium permanganate, potassium dichromate, chlorine, or sulphurous 
acid ; of these methods, the hydrogen dioxide process is preferable, 
as it is least liable to injure the oil, while the use of other bleaching 
agents necessitates repeated washing of the oil with water and even 
weak alkali solutions to remove acid oxidation products. 

The adulteration of fixed oils is effected by mixing the finer aud 
more valuable oils with inferior and cheaper varieties, and as the 
crude methods of former years are no longer practised, a better 
knowledge of the chemical behavior of fats and fixed oils is neces- 
sary at the present day. Caustic and carbonated alkalies are prac- 
tically without effect upon fats and fixed oils in the cold unless free 
acids, due to rancidity, be present ; a more or less uniform mixture 
results, but no chemical change is produced. If boiled together 
with solutions of alkali hydroxide or carbonate, all fats and fixed 
oils used in pharmacy, with the exception of lanolin, wax, and sper- 
maceti, readily undergo saponification and form water-soluble com- 
pounds ; the amount of caustic soda or potassa necessary to saponify 
one gramme of fat varies for each fat and fixed oil, and expressed in 
milligrammes is known as Koettstorfer's saponification factor, by 
means of which the purity of fixed oils may be tested. Since fatty 
compounds are capable of uniting with iodine, a method for the de- 
tection of admixtures in fixed oils has been proposed by Huebl, the 
quantity of iodine combining with a given weight of the oil being 
different in each case; the number of grammes of iodine absorbed 
by 100 grammes of any fixed oil expresses the iodine addition factor 
of that oil. (These two methods are more fully explained under the 
head of Pharmaceutical Chemistry.) 

Drying oils may be distinguished from non-drying oils by their 
behavior with sulphuric and nitrous acids. If 50 Gm. of a fixed 
oil be mixed with 10 Cc. of concentrated sulphuric acid, heat will 
be developed varying in intensity for different oils, the drying oils 
always showing the greatest rise in temperature ; thus, while olive 
oil increases 42° C. in temperature, castor oil 47° C, and oil of 



190 GENERAL PHARMACY. 

almond 52° C, hempseed oil will show a rise of 98° C. and linseed 
oil 103° C. When mixed with nitrous acid, non-drying oils will 
gradually be converted into a solid mass, while drying oils remain 
fluid even after prolouged contact, although a few become somewhat 
thicker. The test is made by agitating for a short time one part of 
copper foil with five parts each of nitric acid and the oil, and setting 
the mixture aside for about six hours, when solidification is generally 
completed. Among the prominent non-drying oils are olive oil, 
castor oil, almond oil, lard oil, sesame or benne oil, mustard oil, 
colza or rapeseed oil, and groundnut oil, while the following belong 
to the drying oils : linseed oil, cottonseed oil, poppyseed oil, hemp- 
seed oil, and walnut oil. 

Animal fats are usually obtained by rendering over a slow fire 
and then straining to remove the particles of membranous tissue ; 
like vegetable fats, they should be preserved in well-closed vessels 
impervious to fat, in a cool place, protected against moisture and 
light. Of the fats and fixed oils recognized in the Pharmacopoeia, 
seven are of animal and eight of vegetable origin. 

The Official Fats and Fixed Oils. 

Adeps. Lard. This is the prepared abdominal fat of the hog de- 
rived from the so-called leaves, and is preferably collected in the winter 
or early spring, as it has a higher fusing-point than that collected in 
summer. It is obtained by removing, as far as possible, all foreign 
matter, washing well with water after the fat has been cut into small 
pieces and then melting with a moderate heat, or a steam or water 
bath, until all water is dissipated. Lard is slightly soluble in alcohol 
and readily so in ether, chloroform, carbon disulphide, or benzin ; 
it fuses at 38°-40° C. (100.4°-104° F.) to a clear colorless liquid, 
and at 30° C. (86° F.) again returns to a soft solid. In order to 
render lard inodorous, to each pound of it melted, fifteen grains of 
powdered alum and thirty grains of table salt are added, and the 
heat continued as long as a scum rises ; this is removed, the lard is 
allowed to cool, and then well washed with a constant stream of 
water until all traces of the salts have been removed. Finally, the 
fat is remelted and the heat continued until all the water has been 
evaporated. Lard consists of a liquid fat known as olein and a solid 
fat known as stearin, which can be readily separated by expression at 
low temperatures ; the liquid fat is officially employed under the name 
of lard oil, but the stearin alone is not used in pharmacy. Owing 
to the presence of these two fats, melted lard when allowed to cool 
slowly will become granular, the more solid fats partially separating, 
hence no smooth product can be obtained ; lard and its preparations 
when melted should always be stirred until cool, or at least until 
a uniform creamy mixture results. Commercial lard is liable to 
contain starch, alkalies, added to improve the whiteness, and table 
salt mixed with it as a preservative; these substances the Pharma- 



C 'LASSIFICA TION OF Nu I TUBAL PR 01) I X IS. 191 

copoeia requires to be absent in the medicinal lard, as shown by 
appropriate tests. Since lard may be adulterated with cottonseed oil, 
the official silver nitrate test for this admixture should not be omitted. 
Pare lard is liable to become rancid if kept for some time, hence the 
Pharmacopoeia directs its preservation by benzoinating. This is done 
by suspending two parts of coarsely powdered benzoin, contained in 
loosely textured cloth, for two hours, in 100 parts of melted lard at a 
temperature not exceeding 60° C. (140° F.), in a covered vessel, then 
straining and cooling. The balsamic principles of benzoin are solu- 
ble in the melted fat, and protect it afterward against change. In 
summer, the preparation which is officially known as Adeps Ben- 
zoinatus should contain 5 per cent, of white wax, in place of a like 
quantity of lard, to render it firmer. 

Adeps Lance Hydrosus. Hydrous Wool-fat. Lanolin. The official 
article is a mixture of 70 per cent, of purified wool-fat and 30 per 
cent, of water. The wool of sheep contains a natural grease, which 
is readily removed in the process of washing the wool, and is of com- 
plex composition, containing about 30 per cent, of free fatty acids, 
besides numerous fatty compounds ; the so-called cholesterin fats are 
the constituents sought for the production of lanolin. The crude fat 
is first treated with weak alkaline solutions, whereby a creamy mix- 
ture is obtained, which is placed in centrifugal machines and sepa- 
rated into two layers ; of these the upper layer is treated with calcium 
chloride, which precipitates impure lanolin, to be purified by repeated 
melting and washing. Final extraction with acetone yields pure 
anhydrous lanolin of yellowish brown color and characteristic odor, 
which, when mixed with 30 per cent, of water, constitutes the official 
hydrous wool-fat. The chief advantage of lanolin over other fats 
lies in its miscibility with large amounts of water (twice its weight) 
without losing its ointment-like character. The Pharmacopoeia de- 
mands for the official article the entire absence of alkalies, glycerin, 
and free fatty acids. Hydrous wool-fat has about the same fusing- 
point as lard, and forms turbid solutions with ether and chloroform ; 
it is saponified with difficulty. 

Cera Alba; Cera Flava. White Wax ; Yellow Wax. Beeswax. 
The only wax recognized by the Pharmacopoeia is that secreted by 
the bees and used by them in the construction of the honeycomb. 
To obtain the wax, the honey is drained from the comb, which is then 
expressed, melted in water, and after the impurities have subsided, 
run into moulds and cooled. This constitutes yellow wax, from 
which white wax is made by a process of sun-bleaching, as follows : 
Melted wax is again solidified in the form of thin ribbons or bands, 
by allowing it to flow over wet revolving cylinders ; these bands are 
moistened with water, and exposed to suulight in the open air. After 
exposure for some time the color disappears in spots and the wax is 
again melted, re-solidified and treated as before, the process being 
repeated from time to time until the wax is completely bleached, when 
it is finally melted and run into moulds ; besides losing its color, 



192 GENERAL PHARMACY. 

wax thus treated is somewhat changed by long exposure to light and 
air, and is more disposed to rancidity than yellow wax, as is notice- 
able in the modified odor. Pure yellow wax melts at 63°-64° C. 
(145°- 147. 2° F.), white wax at 65° C. (149° P.)- they differ from 
true fats in not containing glycerin, and in not forming soap when 
boiled with solution of alkali carbonates. Wax is completely dis- 
solved by ether and chloroform, but not by boiling alcohol and cold 
benzene or carbon disulphide. Besides the crude adulterations 
readily observed in melted wax, tallow and other fats, as well as vege- 
table wax, resin, and paraffin, are frequently mixed with it ; they can 
be quickly detected by the pharmacopoeial tests. Fats and resin may 
be taken up by a boiling solution of sodium hydroxide or by petro- 
leum benzin, neither of which dissolves the wax ; paraffin is readily 
detected by heating the suspected wax with concentrated sulphuric 
acid, which destroys the wax but leaves the paraffin unaffected. If 
pure wax be melted and allowed to cool slowly, it will always con- 
geal with a level surface, but if paraffin in any form be present, the 
surface will be more or less concave, according to the extent of adul- 
teration. 

Cetaceum. Spermaceti. Spermaceti is obtained by expression 
from the fatty secretion found in the cranial cavity of the sperm 
whale. Before the animal is killed, the fat is liquid, but afterward 
congeals to a yellow mass; by expression a yellow oil is removed, 
the residue is melted, washed with weak potassa solution and water, 
and finally allowed to congeal. Spermaceti is apt to become yellowish 
and rancid by age and when exposed to air ; it melts at about 50° C. 
(122° F.), and is soluble in boiling alcohol, ether, chloroform, carbon- 
disulphide, and fixed and volatile oils. It can be powdered by tritu- 
ration in a mortar after sprinkling with alcohol. Fused with potassa, 
spermaceti is saponified, but not if boiled with a solution of alkali 
carbonate, which fact serves to detect the presence of stearic acid as 
an adulteration. 

Oleum Adipis; Lard Oil. The fixed oil expressed from lard at a 
low temperature. It congeals near 0° C. (32° F.), but already at 
10° C. (50° F.) begins to deposit granular fat, hence, to remain fluid, 
it should be kept at or above 15.5° C. (60° F.) The most likely 
adulterations are cottonseed oil and paraffin oils ; the former can be 
detected by heating the oil with an acidulated alcoholic solution of 
silver nitrate, when the mixture should remain colorless. Lard oil 
should be perfectly saponified by heating with potassa, water, and 
alcohol ; the separation of an oily layer would indicate paraffin oils. 
The yield of lard oil is equal to about 60 per cent, of the weight of 
the lard expressed. 

Oleum Amygdalce Expressum. Expressed Oil of Almond. This 
oil, also commercially known as oil of sweet almond, is obtained by 
expression from the bitter as well as the sweet almond, the yield from 
the latter source being about 20 per cent, greater than from the 
former. The yellowish color of the commercial oil is due entirely 



CLASSIFICATION OF NATURAL PRODUCTS. 193 

to the colored episperm, for if blanched almonds be expressed, a 
colorless oil will be obtained. Expressed oil of almond is soluble to 
some extent in cold alcohol ; it remains perfectly clear at — 10° C. 
(14° F.), and does not congeal until cooled to —20° C. (—4° F.). 
The oil is largely adulterated with the oils of peach and apricot 
kernels, which can be detected by shaking together 1 volume each 
of fuming nitric acid and water and 2 volumes of the suspected oil ; 
a whitish mixture, free from orange or reddish color, results if the 
oil is pure. The development of a brownish color, with the same 
test, would indicate the presence of cottonseed, groundnut, sesamum, 
or poppyseed oils. 

Oleum Gossypii Seminis. Cottonseed Oil. The official cottonseed 
oil is a refined bleached oil, for the crude product, obtained by 
hydraulic pressure from the seed, has a brown color and linseed-like 
odor, and contains considerable quantities of albuminous matter. 
After subsiding, the crude oil is treated with superheated steam, and 
finally well shaken with heated weak alkali solution. The yield of 
oil from cottonseed varies from 12.5 to 20 per cent. ; the residue, or 
oil-cake, is considered a valuable cattle food and fertilizer. Cotton- 
seed oil congeals when cooled to 0° or —5° C. (32° or —23° F.), and 
is instantly colored dark reddish-brown in contact with concentrated 
sulphuric acid ; it belongs to the drying oils, but shaken with nitric 
acid and water it gradually forms a colored semi-solid mass. The 
chief use of cottonseed oil is as a substitute for more expensive fixed 
oils, as in the case of some of the official liniments, and there is no 
doubt that it is extensively employed as an adulteration for almond, 
olive, and other oils. When heated with an acidulated alcoholic 
solution of silver nitrate the oil assumes a reddish-brown color, which 
serves as a test for its detection. 

Oleum Lini. Linseed Oil. The Pharmacopoeia demauds an oil 
expressed without heat, which, as a rule, is not readily obtainable, 
since hot pressure increases the yield nearly 50 per cent. Extraction 
with petroleum benzin or carbon disulphide shows still better results : 
thus, cold pressure, 16 to 20 per cent. ; hot pressure, 22 to 28 per cent. ; 
extraction, 33 per cent. Cold-pressed linseed oil is lighter in color than 
the other varieties ; when boiled it darkens in color and thickens, losing 
about 6 to 8 per cent, in weight. The oil is quite soluble in absolute 
alcohol, and forms a clear mixture with an equal volume of official 
alcohol, but becomes turbid if the proportion of alcohol is doubled ; 
it does not congeal above — 20° C. ( — 4° F.). Linseed oil is always 
slightly acid and is readily saponified by alkalies ; it is the best dry- 
ing oil known and should not be even partially solidified if shaken 
with nitric acid and water for a long time, by which meaus the pres- 
ence of non-drying oil may be detected. As linseed oil may be adul- 
terated with paraffin oils, the Pharmacopoeia recommends shaking an 
aqueous solution of linseed oil soap with an equal volume of ether, 
which latter, after decantation, should not show a bluish fluorescence 
nor leave an oily residue upon evaporation. 

13 



194 GENERAL PHARMACY. 

Oleum Morrhuce. Oleum Jecoris Aselli. Cod-liver Oil. Medi- 
cinal cod-liver oil should always be procured from fresh livers, 
by the aid of a gradually increased steam heat not exceeding 60° C. 
(140° F.) ; the oil is allowed to separate from the watery fluid, 
and after it has been frozen is expressed in canvas bags, whereby 
a pure only slightly colored oil is obtained, the hard yellow residue, 
consisting of stearin and tissue, being rejected for other purposes. 
Cod-liver oil thus carefully prepared keeps well in completely filled 
vessels, and when cooled to 0° C. (32° F.) should deposit no solid 
fats ; it belongs to the drying oils, and if exposed to the air soon 
thickens and assumes a disagreeable strong odor and taste. The 
color reactions with sulphuric acid mentioned in the Pharmacopoeia 
are due to the presence of certain biliary constituents and are very 
pronounced. Cod-liver oil has a slight acid reaction which increases 
with age. The more probable adulteration consists of seal oil and 
other fish oils, which can be detected by testing with fuming nitric 
acid ; cod-liver oil turns red, then bright rose-red, and finally lemon- 
yellow ; seal oil shows at first no change of color, and other fish oils 
become blue at first and afterward brown and yellow. 

Oleum Olivce. Olive Oil, The finest quality of olive oil is that 
obtained by cold expression from the flesh only of the ripe fruit, and is 
known commercially as "virgin oil;" a second quality is expressed 
from the residue, after the same has been mixed with water. Good 
olive oil is of a pale yellow or light greenish-yellow color, while the 
inferior grades, often expressed from fermented olives, are of a deeper 
green. It becomes cloudy at 10° C. (50° F.), and congeals at 0° C. 
(32° F.), to a whitish granular mass. Olive oil is, no doubt, largely 
adulterated with cottonseed oil, groundnut oil, poppyseed oil, and 
sesamum oil ; when heated with an acidulated alcoholic solution of 
silver nitrate, the oil, if pure, should retain its original pale-yellow 
color without becoming reddish or brown. Sesame oil is best de- 
tected by a special test given in the Pharmacopoeia, and which is 
characteristic for that oil. A solution of soap made from the suspected 
oil and potassa is decomposed with sulphuric acid, and the liberated 
fatty acid, freed from water, is shaken with hydrochloric acid ; if the 
mixture turns green, sesame oil is present, and on the subsequent 
addition of sugar, the mixture, after shaking, assumes a violet or 
crimson tint. This is known as Baudouin's test. 

Oleum Eicini. Castor Oil, This well-known oil is produced in 
very large quantities in this country in the city of St. Louis; in 
order to increase the yield of the oil, the seed is frequently heated to 
about 60° C. (140° F.), before expression, and the oil afterward 
heated with water to remove albuminous matter. The yield of oil 
by cold expression is about 25 to 30 per cent,, and by hot expression, 
38 to 45 per cent. Castor oil when cooled to 0° C. (32° F.), be- 
comes turbid, but does not congeal until the temperature has been 
reduced to— 18° C. ( — 0.4° F.); it is soluble in all proportions in 
absolute alcohol or in glacial acetic acid, and in three times its volume 



CLASSIFICATION 01 NATURAL PRODUCTS. 195 

of a mixture of 19 volumes of alcohol and 1 volume of water, which 
distinguishes castor oil from other fixed oils. Castor oil is rarely 
adulterated and is readily saponified by alkalies. 

Oleum Sesami. Sesame Oil. Benne Oil. Teel Oil. Sesame oil is 
obtained both by cold and hot expression to the extent of about 50 
per cent, of the weight of the seed. It congeals at — 5° C. (23° F.), 
to a yellowish-white mass, and is converted into a brownish-red 
jelly when mixed with concentrated sulphuric acid. When shaken 
with an equal volume of concentrated hydrochloric acid, it assumes 
an emerald-green color, which, upon addition of sugar and further 
shaking, changes to blue, violet, and finally, deep crimson. Sesame 
oil is sometimes found as an admixture in olive oil and expressed oil 
of almond. 

Oleum Theobromatis. Oil of Theobroma. Butter of Cocoa. Oil of 
theobroma is the only fixed oil recognized by the Pharmacopoeia 
which is solid at ordinary temperature; it is brittle at 15° C. (59° F.), 
and melts at from 30° to 33°C. (86° to 91.4° F.). The oil is ob- 
tained to the extent of about 40 per cent., by heating the shelled seeds 
to 70° C. (158° F.), and expressing between hot iron plates. Adul- 
terations with stearin, tallow, wax, and paraffin, can be quickly de- 
tected on account of the low fusing-point and high congealing-point 
of the pure oil. The Pharmacopoeia requires that 1 Gm. of oil of 
theobroma dissolved in 3 Cc. of ether at 17° C. (63° F.), and 
plunged into water at 0.° C. (32° F.), shall neither become turbid 
nor deposit a granular mass in less than three minutes; if the mixture, 
after congealing, be warmed to 15° C. (59° F.), it should gradually 
form a perfectly clear liquid. 

Oleum Tiglii. Croton Oil. Croton oil is obtained by expression, 
and does not congeal until cooled to — 16° C. (3.2° F.). Its solu- 
bility in alcohol increases with age, and it has been shown by Seuier, 
of England, that the portion insoluble in alcohol contains the purga- 
tive principle, while the vesicating principle is soluble in alcohol. 
Croton oil is a non-drying oil, but differs from other non-drying oils, 
in remaining liquid if vigorously shaken with fuming nitric acid and 
water and allowed to stand for one or two days ; this behavior serves 
to detect adulterations. 

Glycerin. 

The sources of all glycerin used in pharmacy or sold commercially, 
are various fats, both of vegetable and animal origin, glycerin being 
an invariable constituent of all official fats except spermaceti and bees- 
wax, from which it is liberated whenever such fats are converted into 
soap by the action of moist metallic oxides. It has proven a most valu- 
able solvent and antiseptic in pharmacy, second only to alcohol in this 
respect. Nearly all glycerin now produced in this country is made by 
decomposing fats in large copper digesters; fat and water having been 
put into the digester, steam under' 120 to 150 pounds pressure is in- 
troduced for several hours, whereby the mixture is kept in constant 



196 GENERAL PHARMACY 

agitation and the fat is completely decomposed, the glycerin entering 
into solution in the water, and the non-volatile fatty acids floating 
on the surface of the aqueous solution. The volatile fatty acids are 
allowed to escape with steam through a small orifice in the top of the 
digester. The dilute solution of glycerin is transferred to evapor- 
ating tanks and concentrated until it reaches a density of 28° Baume, 
equal to a specific gravity of 1.24 at 15° C. (59° F.). The crude 
dark amber-colored glycerin thus obtained is introduced into specially 
constructed stills, into which superheated steam enters at a temper- 
ature of about 250° C. (482° F.), carrying the glycerin, in the form 
of vapor, with steam, over into a series of condensers so arranged 
that the glycerin condenses in passing through, at various degrees of 
density; the first condenser, being least cooled, contains the heaviest 
glycerin, the distillate becoming gradually weaker, until, in the last 
condenser, almost pure water is collected. Coloring matter is removed 
by treatment with animal or vegetable charcoal, and the distillation 
is frequently repeated two or three times until the required degree of 
purity has been obtained. The Pharmacopoeia demands at least 95 
per cent, of absolute glycerin, which liquid has the specific gravity 
1.25 at 15° C. (59° F.), and is soluble in water and alcohol in ail 
proportions, as also in a mixture of three parts of alcohol and one 
part of ether, but is insoluble in ether, chloroform, benzene, petro- 
leum benzin, fixed and volatile oils. The most important tests of 
those mentioned in the Pharmacopoeia are : the absence of turbidity 
and color, when glycerin, after dilution with water, is heated and 
mixed with silver nitrate solution, and then exposed to diffused day- 
light for five minutes ; the absence of an offensive or acidulous odor 
when glycerin is heated with diluted sulphuric acid ; the absence of 
dark color when a mixture of equal volumes of glycerin and concen- 
trated sulphuric acid is gently wanned ; and the complete volatility of 
glycerin upon ignition. 

Although official glycerin boils at about 165° C. (329° F.), it is 
readily vaporized from an aqueous solution at 100° C. (212° F.). 

Volatile Oils. 

Volatile oils are those peculiar principles to which, in a majority of 
cases, the odor of plants is due ; they do not all pre exist in the 
plant, some being the result of fermentative action between certain 
constituents of the plant in the presence of water, and others being 
produced by destructive distillation. Volatile oils may exist in 
every part of the plant from the root to the seed, and when several 
oils are present in different parts of the same plant, they will gener- 
ally be found to differ in physical as well as chemical properties; as, 
for instance, the oils of orange obtained from the leaf, flower, and 
rind. They usually occur in separate cells, as glands in the herba- 
ceous portion and rinds of many fruits, or distributed throughout 
the interior tissue, or forming distinct oil tubes, as in the fruit of 



CLASSIFICATION OF NATURAL PRODUCTS. 197 

fennel, anise, etc. The odor of volatile oils, while in some instances 
due to their particular composition, in others appears to be due to 
atmospheric influences, since oil of turpentine and others when recti- 
fied in an atmosphere of carbon dioxide have been found devoid of 
all unpleasant odor, and vet, when again exposed to the air, they soon 
resumed their characteristic odor. With few exceptions, volatile 
oils are lighter than water, and their solubility in water is very 
variable; their specific gravities at 15° C. (59° F.), range from 0.850 
to 1.185. Absolutely pure volatile oils are colorless, but the com- 
mercial varieties are frequently colored yellow, green, blue, red, and 
brown ; the color in most instances disappears when the oil is brought 
into solution. Many volatile oils are completely soluble in glacial 
acetic acid, and all are soluble in alcohol, but in proportions vary- 
ing from less than an equal volume to ten or more. They have but, 
few properties in common with fixed oils, but like these are solu- 
ble in ether, chloroform, and carbon disuiphide. Freshly-prepared 
volatile oils are generally freely soluble in petroleum benzin, but, 
after exposure, they gradually lose this property and often form 
turbid mixtures when shaken with the same. When dropped upon 
filtering paper they cause a stain somewhat resembling that of fixed 
oils, but which is dissipated upon the application of heat ; the stain 
produced by old or partly resinified volatile oils, frequently cannot 
be driven away by heat, but can be readily distinguished from the 
stain of fixed oils, by its shining varnish -like appearance and by its 
complete removal with the aid of warm alcohol, the stain from fixed 
oils being devoid of lustre and insoluble in alcohol. Volatile oils 
are inflammable, and burn with a bright but sooty flame ; exposed 
to air and light they are more or less rapidly oxidized, being gradu- 
ally converted into a viscid oil and finally even into a solid resin. 
They never become rancid in the sense mentioned under fixed oils, 
and do not contain glycerin. Owing to the changes which volatile 
oils undergo through exposure to light and air, they should be pre- 
served in well -stoppered bottles, in a dark place ; amber or yellow T - 
colored glass is best adapted for oil containers, as it intercepts the 
actinic rays of light. The addition of deodorized alcohol or Cologne 
spirit will also preserve the fine aroma of such oils as lemon and 
orange, not more than 5 per cent, by volume being necessary. Res- 
inified oils may be restored by redistillation with water or weak 
alkali, or, if in small quantities, by Cuvier's method, which consists 
in shaking the oil for fifteen or twenty minutes with a magma 
formed of animal charcoal and a solution of borax, whereby the 
resinified portion is united to the borax aud the oil becomes limpid. 
The whitening of corks in bottles containing volatile oils, is due to 
the presence of ozone produced by the gradual oxidation of the oil. 

The adulterations to which volatile oils are subjected are fixed 
oils, alcohol, and highly rectified petroleum ; frequently, also, the 
higher-priced oils are mixed with cheaper and inferior oils. Fixed 
oils are easily detected by a permanent greasy stain upon paper, and 



198 



GENERAL PHARMACY. 



by a non- volatile residue when the suspected oil is subjected to distil- 
lation. Alcohol may be tested for in several ways. If the oil be 
shaken in a graduated tube with an equal volume of water or 
glycerin, and then allowed to stand at rest, auy diminution in the 
volume of the oil would indicate alcohol, and approximately also the 
proportion present; if considerable alcohol be present, the character- 
istic lambent blue flame of burning alcohol will be observed if a 
portion of the suspected oil is ignited in a dark room ; fused calcium 
chloride and dry potassium acetate are insoluble in volatile oils, but 
in the presence of alcohol become soft and even liquid, depending 
upon the proportion of alcohol ; potassium acetate and sulphuric acid 
added to volatile oils will generate acetic ether if alcohol be present, 
which may be detected by its odor ; and auiline-red is insoluble in pure 
volatile oils, but colors these red in the presence of alcohol. Adul- 
terations with rectified petroleum are often not easily detected, and 
may require a careful chemical examination; for it, as well as for 
the inferior volatile oils, the Pharmacopoeia prescribes appropriate 
tests under the head of the respective oils likely to be thus contami- 
nated. The different optical behavior of volatile oils is also often of 
great value in the search for adulterations. 

The usual method of obtaining volatile oils is by distillation, and 
in some instances the plan is still followed of placing the oil-yielding 



Fig. 19(1 




Distillation of volatile oils by steam. 



CLASSIFICATION OF NATURAL PRODUCTS. 



199 



material in an iron or copper still provided with a perforated dia- 
phragm or false bottom, and adding sufficient water to barely cover 
the material, after which direct heat is applied until the water boils, 
and then continued as long as the distillate shows the presence of 
any volatile oil. Although the boiling-points of volatile oils are 
considerably above that of water, the oils pass over rapidly with the 
vapor of boiling water, and in the leading establishments in this 
country and Europe, volatile oils are now distilled by passing steam 
under pressure into stills which contain the material on a series of 
perforated trays extending across the inner body of the still ; by 
this method compaction is avoided, the steam can readily penetrate 
every particle of the material, and a much finer quality of oil results, 
since prolonged contact with boiling water has a deleterious effect 
upon many oils. Fig. 196 represents the distillation of volatile 
oils by steam, as carried on at the factory of Fritzsche Bros., at 
Garfield, N. J.; the large still in the rear has a capacity of 1000 
pounds of cloves. Whenever the volatile oil is deeply imbedded in 
the material, as in the case of cloves, cubebs, and many barks and 
seeds, it is necessary that this be first reduced to a coarse powder so 
as to facilitate the liberation of the oil. The distillate, which is a 
mixture of oil and water, is collected in suitable receivers, either in 
the form of Florentine flasks with a single outlet tube near the bottom 
and reaching nearly to the top, as shown in Fig. 197, or of tall cylin- 
ders provided with two tubes, a long one near the bottom and a 
short one near the top ; as the dis- 
tillate cools it separates into two 
distinct layers, one consisting of 
pure oil and the other of water 
still holding some oil in solution and 
suspension, which is subsequently re- 
gained, either by conveying the water 
back direct to the still or by distilling 
the water in separate stills, frequently 
after addition of table salt to facilitate 
the separation of the oil. As a rule, 
the layer of oil floats on top, except in 
those cases in which the oil has a spe- 
cific gravity above 1.000, as the oils 
of cloves, cassia, gaultheria, etc. The 
lower layer will flow off through the 
long tube as soon as the liquid in the 
flask or cylinder reaches the height 
of the curve in the tube, and will 
continue to flow as long as distillation 
continues. When the upper layer 
fills the vessel, the latter must be 
changed, or if it is provided with two tubes, as shown in Fig. 198, 
the liquid will pass out through the short tube into another recep- 



FiG. 197. 




Florentine flask for collecting- 
volatile oils. 



200 



GENERAL PHARMACY. 



tacle ; thus the two layers of liquid are withdrawn simultaneously 
almost as fast as separation takes place. 



Fig. 198. 



f\ 




Fig. 199. 



Receiver for volatile oils, with two outlets. 

Besides distillation, other methods are employed for obtainiug 
volatile oils, such as expression by hand or machine, and extraction 
by meaus of suitable solvents ; for certain flowers possessing delicate 
fragrance, such as the violet, heliotrope, mignonette, tuberose, etc., 
which do not contain volatile oils in appreciable quantities, the treat- 
ment with fats by maceration and digestion, or the pneumatic process, 
is resorted to for obtaining the odorous principles. 

Expression is particularly suited for those oils contained in the 
epidermal cells of the fruit, as in the natural order of Aurantiacea?, 

and yields oils of superior quality ; 
the oils of orange and lemon are very 
sensitive to heat, and hand-pressed oils 
always command a higher price, on ac- 
count of their delicate aroma. A special 
apparatus, known as ecuelle apiquer (a 
pricking basin), see Fig. 199, is exten- 
sively employed in Southern France ; 
it consists of a tin basin about 8 
inches in diameter, studded with nu- 
merous (150) short, very pointed 
brass needles, and provided with a 
hollow handle. The operator holds 
the basin in one hand and with the 
other, while rotating the fruit, he 
continually presses it against the 
needle-points, thus rupturing the oil- 
cells and causing the oil to flow into 
the handle, whence it is transferred to 
larger vessels and allowed to separate from any fruit juice with which 
it has become contaminated. Another method of hand-pressing is 




Pricking basin for obtaining hand- 
pressed volatile oils. 



CLASSIFICATION OF NATURAL PRODUCTS. 201 

practised in Italy, known as the sponge method ; the rind of the fruit 
is separated from the pulp and cut into three or four strips, which are 
held over a sponge and expressed by convex flexion, whereby the cells 
are burst and the oil is ejected. When the sponge has become satu- 
rated with oil, it is expressed into an earthen vessel. The residual 
rind is frequently mixed with water and again expressed in linen 
sacks, to yield a lower grade of oil. 

The solvents employed for the extraction of volatile oils are 
petroleum benzin, ether, carbon disulphide, acetone, etc., solution 
being effected, in tightly closed apparatus, by means of maceration 
and percolation. After complete extraction of the volatile oil, the 
solvent is recovered by distillation at temperatures not affectiug the 
oil, and the residue must then be further purified by rectification. 
The chief drawback to this method is the possible extraction of other 
substances besides volatile oils, such as resin, fat, etc., which are 
sometimes eliminated with great difficulty ; hence it is not employed 
to any great extent. 

The process of maceration is confined to the extraction of delicate 
odors from flowers, and belongs more properly to the art of per- 
fumery than to pharmacy ; although the odors are quite marked 
and persistent, the volatile oil in many flowers is present in such 
small quantity only that it cannot be recovered by distillation, and 
in some cases is injured by even moderate heat. Complete absorp- 
tion of the odorous principle by fats, in the cold, is practised on a 
large scale in France, where the process is known as enfleurage ; 
bland, inodorous fats, such as purified lard, tallow, olive oil, benne 
oil, and cottonseed oil, being used for the purpose. In the last three 
cases the flowers are left in contact with the oil, in closed vessels, for 
some time and then strained. When solid fats are used, they are 
thinly spread on plates of glass, and then covered with flowers, which 
are renewed from time to time as long as the fat continues to absorb 
the odor. The fats, impregnated with the odor of the flowers, are 
finally scraped from the glass, and constitute the well-known French 
pomades so extensively employed in the manufacture of fine per- 
fumery. In order to extract the odor, the pomade is repeatedly 
shaken (washed) with deodorized alcohol and the solution exposed 
to cold in special cylinders, called crystallizers, whereby all trace of 
fat is removed. 

The pneumatic method consists in passing a current of air into a 
vessel filled with fresh flowers, whereby the air becomes laden with 
perfume, and is then passed into another vessel containing fat kept 
in a fine state of division, so that intimate contact between the air 
and fat is effected, and thus the odor is transferred to the fat. 

Very few volatile oils are of simple composition, and some are 
even known to contain six or eight distinct bodies. While formerly 
many arbitrary and erroneous notions were entertained regarding 
the nature of volatile oils, much light has been shed upon their true 
character by Wallach and others, during the past ten or twelve 



202 GENERAL PHARMACY. 

years. Kegarding the classification of volatile oils, the plan is still 
followed of dividing them into simple hydrocarbons or terpenes 
(containing no oxygen), oxygenated oils, nitrogenated oils, sulphu- 
retted oils, and empyreumatic oils ; but the division into elseoptens 
and stearoptens is no longer maintained. The chemical character 
and composition of volatile oils will be considered further on, when 
the student's knowledge of chemistry will better fit him for a proper 
understanding of the subject. 

1. Carbo-hydrogen Oils, or Terpenes. The carbo-hydrogen oils 
are the simplest volatile oils known, being composed of carbon 
and hydrogen only, and are derived mainly from the natural orders 
Coniferse, Leguminosse, and Piperaeese. They are divided into 
hemiterpenes, terpenes, sesquiterpenes, diterpenes, etc. Some of 
these are frequently found present also in oxygenated oils. The 
terpenes proper occur in five isomeric forms (having the same cen- 
tesimal composition, but different properties), known as pinene, 
dipentene, limonene, sylvestrene and phellandrene ; of these sometimes 
two or three are found associated in the same oil. As a class, the 
carbo-hydrogen oils are the least soluble in alcohol and water, and 
have specific gravities ranging from 0.850 to 0.900. They readily 
become resinified when exposed to the air, and when left in contact 
with alcohol and nitric acid gradually absorb water and yield crystal - 
lizable compounds. They react violently with iodine, and are con- 
verted into a hard resinous mass by nitric acid. 

The official members of this class are oil of copaiba, oil of cubeb, 
oil of erigeron, oil of juniper, oil of savin, and oil of turpentine. 

2. Oxygenated Oils. These oils, as the name indicates, contain 
oxygen, and are composed of variable mixtures of terpenes and other 
bodies, such as alcohols, aldehydes, ethers, acids, ketones, phenols, 
etc., which can be separated by fractional distillation. Oxygenated 
oils are widely diffused in plants, but the larger number are derived 
from the natural orders Umbelliferse, Labiate, Lau raceme, Myr- 
tacese, and Composite. The majority of oxygenated oils are soluble 
in an equal volume of alcohol or glacial acetic acid, and many are 
soluble in these two liquids in all proportions. They are far more 
soluble in water than the simple terpenes, and hence are largely used 
in the preparation of medicated waters. Decreased solubility in 
alcohol, or in a mixture of alcohol and water, is frequently made a 
test for adulteration with carbo-hydrogen and other oils. 

While the majority of oxygenated oils are lighter than water, a 
few w T ill sink when dropped into water, the highest specific gravity 
for volatile oils being found in this class, namely, 1.185 at 15° 
C. (59° F.). Some, owing to their peculiar chemical composition, 
will form a solid mass when shaken with an equal volume of con- 
centrated potassa or soda solution, while others show a similar reac- 
tion with sodium bisulphite. Upon exposure to low temperatures, 
some of the oils of this class thicken and even congeal to a solid mass, 
which fact is utilized as a test for their quality. The value of oxy- 



CLASSIFICATION OF NATURAL PRODUCTS. 203 

genated oils lies, as a rule, in the oxygenized compounds which they 
contaiu, and which are present in the different oils in proportions 
varying from 1 to 90 per cent. By producing these synthetically, 
artificial oils, identical with the natural, have been made, of which 
the official methyl salicylate or artificial oil of wintergreen (identical 
also with the natural oil of sweet birch) is an example. The Phar- 
macopoeia recognizes a single concrete volatile oil, camphor, which 
can be appropriately classed among the oxygenated oils, since its 
chemical composition shows it to be a pure oxidized hydrocarbon. 

The official oxygenated oils are those of anise, bergamot, betula, 
cajeput, caraway, cloves, chenopodium, cinnamon, coriander, euca- 
lyptus, fennel, gaultheria, hedeoma, lavender flowers, lemon, orange 
flowers, orange peel, peppermint, spearmint, myrcia, nutmeg, 
pimenta, rose, rosemary, santal, sassafras, and thyme. Of these, 
the oils of bergamot, orange peel, and orange flower consist almost 
entirely of limonene, one of the isomeric terpenes, containing less 
than 3 per cent, of undetermined oxygenated bodies. 

3. Nitrogenated Oils. Some plants do not produce volatile oils in 
nature, but contain certain principles which, in the presence of water, 
react upon each other, causing the formation of new compounds, one 
of which is a volatile oil ; such is the case with certain plants belong- 
ing to the natural order Rosaceae, sub-order Amygdalae. The vola- 
tile oil, when absolutely pure, contains no nitrogen, but the name 
nitrogenated oils has been given to this class because in their forma- 
tion they are always accompanied by a nitrogenized substance, hy- 
drocyanic acid, which is present in variable proportion and which 
lends to the oils their poisonous character. The only official nitro- 
genated oil is the oil of bitter almond, which is prepared by mixing 
freshly powdered bitter almonds with the residue left after express- 
ing the fixed oil from bitter and sweet almonds, adding water, and 
distilling at a moderate heat. The specific gravity of the oil ranges 
from 1.060 to 1.070 at 15° C. (59° F.), and that of the purified oil is 
about 1.045. The oil is sometimes adulterated with nitrobenzene or 
artificial oil made from toluene. Bitter almonds, like peach and 
cherry seeds, contain both the albuminous ferment and the peculiar 
compound, amygdalin, necessary for the reaction, while sw r eet almonds 
contain only the ferment, and hence will yield no volatile oil unless 
mixed with the bitter variety. The hydrocyanic acid present in oil 
of bitter almond sometimes amounts to as much as 6 or 7 per cent., 
and may be removed by shaking the oil with ferrous chloride and 
lime-water and then rectifying by distillation. Oil of bitter almond 
is soluble in 300 parts of water and in all proportions of alcohol. 

4. Sulphuretted Oils. Like the preceding class, these oils are the 
result of fermentative action, in which the living plant takes no part 
except to provide the necessary active principles for the subsequent 
reaction in the presence of water. Sulphur is present in the oils, 
combined with certain organic radicles, in the form of sulphide or 
sulphocyanate. Nearly all the oils of this class are obtained from 



204 GENERAL PHARMACY. 

members of the natural order Crucifera?. The Pharmacopoeia recog- 
nizes but one sulphuretted oil, namely, the volatile oil of mus- 
tard, made from black mustard seed, which has a specific gravity 
varying from 1.018 to 1.029 at 15° C. (59° F.). When shaken 
with alcohol and ammonia water and slightly warmed, the oil deposits 
crystals of thiosiuamine ; 3 Gra. of oil should yield not less than 
3.25 Gm. nor more than 3.5 Gm. of such crystals. 

5. Empyreumatic Oils. Among the products of destructive distil- 
lation are certain volatile oils, which are characterized by a peculiar 
tarry odor, an acid reaction and a somewhat bitter taste. They are 
lighter than water, sparingly soluble iu that liquid, but readily solu- 
ble in alcohol. Oil of cade and oil of tar are the only empyreumatic 
oils recognized in the Pharmacopoeia ; the former is obtained by the 
dry distillation of the wood of the prickly cedar (juniperus oxy- 
cedrus) and the latter by distillation of tar. 



PART II. 

PRACTICAL PHARMACY. 



The study of practical pharmacy involves both galenical aud 
extemporaneous pharmacy, the former pertaiuing to the various 
preparations of drugs, the latter to the many operations of the dis- 
pensing counter. The different classes of plant products used in 
medicine, as well as the various methods of solution and separation, 
have been considered in previous chapters ; the numerous prepara- 
tions of drugs will be treated after a plan which, for a number of 
years, has proven satisfactory to students, and although not based on 
a strictly symmetrical arrangement, is probably in keeping with the 
advance made by them in other branches of study up to this point. 

The official preparations may be divided into those of a strictly 
pharmaceutical character and those involving chemical action ; the 
latter class will be considered under the head of pharmaceutical 
chemistry, where the preparations of each element or compound will 
be grouped together. 

The galenical preparations of the Pharmacopoeia may be classified 
as follows : 1, Waters; 2, Solutions or Liquors; 3, Decoctions and 
Infusions ; 4, Syrups ; 5, Mucilages, Honeys, and Glycerites ; 6, 
Elixirs; 7, Spirits; 8, Tinctures; 9, Wines and Vinegars; 10, Fluid 
Extracts; 11, Extracts; 12, Oleoresins and Resins; 13, Collodions; 
14, Emulsions; 15, Mixtures; 16, Pills; 17, Lozenges and Confec- 
tions; 18, Powders and Triturations; 19, Granular Effervescent 
Salts; 20, Cerates and Ointments; 21, Liniments and Oleates; 22, 
Plasters and Suppositories. 

The operations of the dispensing counter are intimately associated 
with the various preparations of drugs officially recognized, aud, 
instead of treating them separately under a special head, it is thought 
most convenient to consider them in connection with some of the suit- 
divisions named above, particularly as eight classes of the official 
galenical preparations require remarks anH explanations, which apply 
equally to the details of dispensing pharmacy. Certain forms of 
administering medicines, not as yet recognized in the Pharmacopoeia, 
but which, of late years, have come into use extensively, such as 
Compressed Tablets, Tablet Triturates, Hypodermic Tablets, Medi- 
cated Disks, etc., may be looked upon as modifications of the official 
class of lozenges and studied in connection with these. 



CHAPTEE XIII. 

THE OFFICIAL WATERS. 

The official waters include common and distilled water, as well as 
those known as medicated waters ; the latter are all solutions of vola- 
tile substances, and were it not for this pharmacopceial classification, 
four of them might be considered as more appropriately belonging to 
the class of liquors or solutious proper, instead of medicated waters, 
namely, aqua ammonias, aqua ammonias fortior, aqua chlori, and aqua 
hydrogenii dioxidi. 

The U. S. Pharmacopoeia directs three different methods for the 
preparation of medicated waters ; namely, by simple agitation of the 
medicinal ingredient with cold water, by trituration of essential oils 
with precipitated calcium phosphate and water, and by distillation. 
In England and Germany the second method is not practised, the 
pharmacopoeias of both countries directing all aromatic waters to be 
made by distillation. Another excellent method for making aromatic 
waters is that known as the hot- water method ; the volatile oil may 
either be dropped upon shredded filter paper, and this shaken with 
hot water in a strong bottle for some time, or the oil may be dropped 
into a stone jug and run around the sides, after which the hot water 
is added and agitated until cold ; in either case the finished solution 
is passed through a paper filter, and will be found of excellent quality. 

The most important of the official waters is undoubtedly distilled 
water, because it is intended to be absolutely free from impurities, 
inorganic as well as organic, and is the only kind that should be used 
in making aromatic waters. River water and most spring waters 
contain in solution varying quantities of mineral compounds, and 
frequently carbon dioxide and organic matter, which render the 
water unfit for many pharmaceutical purposes ; boiling and subse- 
quent filtration through sand and charcoal will improve the water, 
but do not remove the salts held in solution, which if present in 
appreciable quantity will cause precipitation if silver nitrate or lead 
acetate be dissolved in the water. The so-called hardness of water 
may be due to the presence of calcium sulphate, and is then known 
as permanent hardness, or it may be due to calcium carbonate held 
in solution by an excess of carbon dioxide, which is always the case 
with spring water coming from limestone districts ; boiling such water 
expels the excessive carbon dioxide, causing the lime-salt to be pre- 
cipitated, whereby it is rendered soft. The directions of the Phar- 
macopoeia to reject the first 10 per cent, of the distillate and to collect 
only 80 per cent, for use, are for the purpose of getting rid of the 



THE OFFICIAL WATERS. 207 

gases and volatile compounds always present in water, and to avoid 
the decomposition-products from ammonia compounds and organic 
matter, with which the last portions of water in the still are apt to be 
contaminated. 

The condensed steam from boiler pipes is frequently sold as dis- 
tilled water, but, unless collected with care, will often be found very 
unsatisfactory and not up to the requirements of the Pharmacopoeia. 
In the manufacture of distilled water all contact with iron and lead 
should be avoided, and either glass or pure tin apparatus used, espe- 
cially for the condensation of the vapors. The occasional appearance 
of confervse (microscopic plants) in distilled water is due to the pres- 
ence of minute spores derived from the air, and may be prevented by 
keeping it in vessels so arranged that the air can enter only after 
having passed through a layer of cotton. Aromatic waters made 
with distilled water are subject to the same difficulties. The addition 
of alcohol, which has been recommended as a preservative measure, 
is inadmissible, because a small quantity would predispose the water 
to acetous fermentation (souring), as has been proven, and larger 
quantities might interfere therapeutically. 

The following classification of the official waters shows, at a glance, 
their strength and mode of preparation : 

Official, Waters made by Agitating the Medicinal Ingredient with 

Coed Water. 

Official Name. Strength. 

Aqua Amygdalae Amara 0.1 per cent, by volume of Oil of Bitter Almond 

Aqua Aurantii Florum 50 per cent, of stronger Orange Flower Water. 

Aqua Chloroformi Saturated. About 0.5 per cent, by volume of 

Chloroform. 
Aqua Creosoti 1 per cent, by volume of Creosote. 

Aqua Hydrogenii Dioxidi About 3 per cent, by weight of pure Hydrogen 

Dioxide, or 10 volumes of available Oxygen. 
Aqua Kosee 50 per cent, of stronger Eose Water. 

Bitter almond water is likely to contain variable proportions of 
hydrocyanic acid, as this acid is usually present in the commercial 
oil ; it is a weak and very uncertain preparation. The German 
Pharmacopoeia directs that bitter almond water shall be made by 
distillation and shall contain 0.1 per cent, of absolute hydrocyanic 
acid ; this corresponds in strength to the distilled cherry-laurel water 
of the British Pharmacopoeia. 

Official Waters made by passing Gases through Water. 

Official Name. Strength. 

Aqua Ammonia? 10 per cent, by weight of gaseous Ammonia. 

Aqua Ammonia? Fortior 28 per cent, by weight of gaseous Ammonia. 

Aqua Chlori 0.4 per cent, by weight of gaseous Chlorine. 

Chlorine water is very prone to change ; it should always be kept 
in well-filled bottles, in a cool, dark place, as air and light hasten 
deterioration. 



208 PRACTICAL PHARMACY. 

Official Waters made by Triturating the Medicinal Ingredient with 
Precipitated Calcium Phosphate and then Mixing with Cold Water 
and Filtering. 

Official Name. Strength. 

Aqua Anisi 0.2 per cent, by volume of Oil of Anise. 

Aqua Campboree 8 Gm. of Camphor in 1000 Cc. 

Aqua Cinnamomi 0.2 per cent, by volume of Oil of Cinnamon. 

Aqua Fceniculi 2 per cent, by volume of Oil of Fennel. 

Aqua Men th» Piperita? 02 per cent, by volume of Oil of Peppermint. 

Aqua Mentha? Yiridis 0.2 per cent, by volume of Oil of Spearmint. 

With the exception of camphor water, this whole class is prepared 
by triturating the oil with twice its weight of calcium phosphate, for 
the purpose of minute subdivision, then adding gradually, under 
constant trituration, sufficient distilled water to make the desired 
volume, and finally filtering the mixture through paper. In the 
case of camphor water, 8 Gm. of camphor are triturated with 5 Cc. 
of alcohol and 5 Gm. of calcium phosphate, after which the prepara- 
tion is finished like the others. 

Other absorbent powders have been used from time to time to 
facilitate the division of the oil, such as magnesium carbonate, pre- 
pared chalk, purified talcum, etc.; but, of all, magnesium carbonate is 
the least desirable, from the fact that a minute quantity of the salt is 
always dissolved, and, in a few cases, compounds with the acids natu- 
rally present in some oils are formed ; cinnamon water made with 
magnesium carbonate is always colored yellowish, whereas, if distilled 
or made with calcium phosphate or purified talcum, a colorless solution 
is obtained. The plan of distributing the volatile oil over purified 
cotton and then bringing it into aqueous solution, by slow r percolation 
with distilled water, which was officially directed in the Pharmacopoeia 
of 1880, yields aromatic waters of fine flavor, but is objectionable, on 
account of the possible bad effects due to prolonged contact of the oils 
with the fingers of the operator. 

Official Waters made by Distillation. 

Official Name. Strength. 

Aqua Aurantii Florum Fortior Saturated. 

Aqua Destillata Absolutely pure. 

Aqua Eosse Fortior Saturated. 

Aromatic waters made by distillation, in many instances, possess a 
more agreeable flavor than the aqueous solution of the corresponding 
volatile oils, which is probably due to the fact that, besides the vola- 
tile oil, other volatile compounds, such as acids or ethers, are present 
in the drug, and, passing over with the steam, remain dissolved in the 
condensed water. In distilling aromatic waters over a naked fire, 
care should be taken to prevent the material from being scorched, 
which can be obviated by placing the drug either upon a diaphragm 
or in a perforated vessel or wire cage, and then suspending this in 
the water. A peculiar odor is observed in some waters immediately 
after they have been distilled and condensed in tin vessels, but not 



THE OFFICIAL WATERS. 



209 



when glass vessels have been used ; if the waters be exposed to the 
air in loosely stoppered vessels, for a few days, this still-odor disap- 
pears and the natural odor of the water becomes apparent. 

The stronger orange flower and rose waters are obtained, on a large 
scale, often as by-products in the distillation of the respective oils ; 
in commerce they are distinguished as of triple or quadruple strength. 
In order to produce a saturated solution of the oil, recourse is had to 




The C'urran Water Still. 
a is a tin-lined copper boiler, c is a galvanized jacket for supporting the boiler over the gas 
burners, and is attachable at b, b ; it is also intended to act as a flue to utilize tbe heat from the 
gas burners on the sides of the boiler, n is a screw cover removable for rilling or cleansing the 
boiler, f is the vapor pipe from the boiler to the condensing coil, p, in the galvanized iron con- 
densing tank, e, which is provided with an inlet for cold water at t, and an outlet for the warm 
water at I. At g is a union for connecting the vapor pipe with the condensing coil, s is the 
outlet for the condensed water, and x is the receiving vessel, j is a perforated ring resting on 
the jacket, and k are vent holes in the ring, through which the exhausted gases pass off. o is 
a removable cover for cleansing out the condensing tank, r is a faucet for drawing off the 
water from the condensing tank. L, L, l are the gas burners, and n the iron frame supporting 
the apparatus and burners. M is a gas cock for regulating the supply of gas to the burners. 

14 






210 PRACTICAL PHARMACY. 

the process of cohobation or redistillation, which consists in distilling 
the same water two or three times with fresh portions of the flowers. 
In some factories, saturated orange flower and rose waters are ob- 
tained, not as by-products, but direct from the flowers, by distilling 
them with relatively small quantities of water; thus triple strength 
water is distilled by using three parts of the flowers to one of water, 
etc. According to Schimmel & Co., of Leipzig, Germany (extensive 
distillers of volatile oils and aromatic waters), sextuple rose water 
represents the highest obtainable concentration, and rose water pre- 
pared from more than six times its weight in roses will not retain the 
whole of its oil in solution, at ordinary temperature. 

For the preparation of distilled water a special apparatus has been 
put upon the market, which is said, by those who have used it, to 
yield an exceptionally pure water and in considerably larger quantity 
than is usually expected from a still of like size. The apparatus, 
which is illustrated in Fig. 200, is known as the Curran Water Still, 
and can be used anywhere if gas and constant water supply be 
available. 

The tin-lined copper boiler has a capacity of five gallons, and from 
it, four and a half gallons of distilled water can be obtained in about 
two and a half hours; this allows the first quart of distillate, carry- 
ing with it all volatile matter, to be rejected, aud also retains a quart 
of water in the boiler. The rapid vaporization of the water in the 
boiler is effected by means of four rose burners consuming jointly 
about twenty-five feet of gas per hour, the generated heat being all 
utilized on the bottom and sides of the boiler, which is surrounded by 
a galvanized iron jacket, as shown in the cut. The vapor-pipes pass- 
ing from the boiler, and the condensing coil, are both heavily lined 
with pure block tin, thus avoiding contact of the water with any 
other metal. There is no pressure on any part of the apparatus, the 
vapor being condensed as fast as generated and the distillate passing 
rapidly into the receiving vessel. Larger sizes of the Curran Water 
Still are made for use with gas or coal, delivering, according to the 
manufacturer's statements, which they guarantee, from four to ten 
gallons of distilled water per hour. 



CHAPTER XIY. 

THE OFFICIAL SOLUTIONS OR LIQUORS. 

The term Liquor is applied in the Pharmacopoeia to all aqueous 
solutions of uon- volatile substances. In Europe the name is applied 
in a less restricted sense, and in England it is not even confined to 
aqueous solutions. Twenty-four liquors are officially recognized, and 
of these, eight are made by simple solution of the medicinal agent in 
water, fifteen involve chemical action in their preparation, and for 
one the Pharmacopoeia gives no process of manufacture. This solu- 
tion — the liquor sodii silicatis — is made on a large scale by manu- 
facturers, being used extensively in the arts, and for medicinal use 
should be of the density officially prescribed. For two of the solu- 
tions — those of potassa and soda — double formulas are given : one 
a simple solution, the other a more tedious chemical process ; the 
former plan is usually followed by pharmacists, while the latter is 
preferred by manufacturers. The official liquors may therefore be 
conveniently divided into two groups, as follows : 



1. Simple Solutions. 
the water. 



The active ingredient is added directly to 



Official Name. 
Liquor Acidi Arsenosi .... 

Liquor Arseni et Hydrargyri Iodidi 
(Donovan's Solution) 

Liquor Calcis (Lime Water) 



Liquor Iodi Compositus (Lugol's 

Solution) 
Liquor Plumbi Subacetatis Dilutus 

Lead Water) 
Liquor Potassse .... 



Liquor Sodse 

Liquor Sodii Arsenatis 



Strength. 
1 Gm. Arsenous Acid 
5 Cc. Diluted Hydrochloric y 

Acid. 

1 Gm. Arsenic Iodide "] 
1 Gm. Red Mercuric > in 100 Cc. 

Iodide. J 

Saturated ; contains about 0.17 per cent. 

of Calcium Hydroxide at 15° C. 

(59° F.), but the percentage decreases 

as the temperature rises. 
5 per cent, of Iodine and 10 per cent, of 

Potassium Iodide. 
3 per cent, by volume of Solution of 

Lead Subacetate (Goulard's Extract I. 
About 5 per cent, of Potassa (Potassium 

Hydroxide). 
About 5 per cent, of Soda (Sodium 

Hydroxide). 
1 Gm. anhydrous Sodium Arsenate in 

100 Cc 



2. Chemical Solutions. The active ingredient is formed in the 
process of manufacture, as the result of chemical action. 



212 



PRACTICAL PHARMACY. 



Official Name. 

Liquor Ammonii Acetatis (Spirit of 
Miiadereru's). Made from ammonium 
carbonate and diluted acetic acid. 

Liquor Ferri Acetatis. Made from fer- 
ric hydroxide, glacial acetic acid, and 
water 

Liquor Ferri Chloridi. Made from iron 
wire, hydrochloric and nitric acids, 
and water. 

Liquor Ferri Citratis. Made from fer- 
ric hydroxide, citric acid, and water. 

Liquor Ferri et Ammonii Acetatis. 
(Basham's Mixture). A mixture of 
tincture of ferric chloride, spirit of 
Mindererus, diluted acetic acid, aro- 
matic elixir, glycerin, and water. 

Liquor Ferri Nitratis. Made from fer- 
ric hydroxide, nitric acid, and water. 

Liquor Ferri Subsulphatis (Monsel's 
Solution). Made from ferrous sul- 
phate, nitric and sulphuric acids, and 
water. 

Liquor Ferri Tersulphatis. Made like 
the preceding, except that more sul- 
phuric acid is used. 

Liquor Hydrargyri Nitratis. Made 
from red mercuric oxide, nitric acid, 
and water. 

Liquor Magnesii Citratis. Made from 
magnesium carbonate, citric acid, 
syrup of citric acid, potassium bicar- 
bonate, and water. 

Liquor Plumbi Subacetatis. Made from 
lead acetate, lead oxide, and water. 

Liquor Potassse. Made from potassium 
bicarbonate, lime, and water. 

Liquor Potassii Arsenitis ( Fowler's 
Solution). Made from arsenous acid, 
potassium carbonate, compound tinc- 
ture of lavender, and water. 

Liquor Potassii Citratis ( Mistura Po- 
tassii Citratis). Made from potassium 
bicarbonate, citric acid, and water. 

Liquor Sodse. Made from sodium car- 
bonate, lime, and water. 

Liquor Sodse Chloratae (Labarraque's 
Solution). Made from sodium car- 
bonate, chlorinated lime, and water. 

Liquor Sodii Silicatis. Made from 
quartz, sodium hydroxide, and water. 

Liquor Zinci Chloridi. .Made from 
granulated zinc, hydrochloric and 
nitric acids, zinc carbonate, and water. 



Strength. 

About 7 per cent, of Ammonium Ace- 
tate. 

About 3 per cent, of anhydrous Ferric 
Acetate. 

About 37.8 per cent, of anhydrous 
Ferric Chloride. 

About 7.5 per cent, of metallic Iron. 

About 0.1 per cent, of metallic Iron. 



About 6.2 per cent, of anhydrous Ferric 

Nitrate. 
About 13.6 per cent, of metallic Iron. 



About 2S.7 per cent, of Ferric Sulphate. 
About 60 per cent, of Mercuric Nitrate. 
About 6.25 Gm. of Magnesia in 360 Cc. 

About 25 per cent, of Lead Subacetate. 

About 5 per cent, of Potassa (Potassium 

Hydroxide). 
1 Gm. Arsenous Acid in 100 Cc. 



About 9 per cent, of anhydrous Potas- 
sium Citrate. 

About 5 per cent, of Soda (Sodium 
Hydroxide). 

At least 2.6 per cent, of available Chlo- 
rine. 

About 33 per cent, of Sodium Silicate 
(a mixture of tri- and tetra-silicate). 
About 50 per cent, of Zinc Chloride. 



CHAPTEE XV. 

DECOCTIONS AND INFUSIONS. 

Decoctions. 

Decoctions are aqueous solutions of the active principles of vege- 
table drugs, prepared at a boiling temperature. This process is ob- 
viously not adapted to drugs containing volatile principles, or those 
whose activity depends upon resinous constituents. Drugs of a very 
close texture, or the active virtues of which cannot be exhausted below 
the temperature of boiling water, are best suited for the process of 
decoction. In former years, decoctions were extensively employed, and 
frequently made by using a large quantity of water and boiling it down, 
in open vessels, to one-half, or even to a less amount. This method 
offered no obvious advantage, and, in fact, often proved decidedly 
disadvantageous, on account of the deleterious eifect upon the con- 
stituents of the drug by long exposure to air and heat. In this 
country at least, decoctions have almost entirely disappeared from 
the physician's armamentarium, and the pharmacist is but rarely 
called upon to prepare them ; the U. S. Pharmacopoeia, since 1880, 
has officially recognized only two of these preparations — namely, 
decoction of cetraria and compound decoction of sarsaparilla. 

Decoctions as well as infusions must always be prepared extem- 
poraneously, since they will readily deteriorate, on account of the 
perishable matter in solution and the absence of alcohol or other 
preservative. 

The Pharmacopoeia gives the following general directions for pre- 
paring decoctions whenever a special strength is not indicated by the 
physician : Put 50 Gm. of the substance, coarsely comminuted, into 
a suitable vessel provided with a cover ; pour upon it 1000 Cc. of 
cold water, cover well, aud boil for fifteen minutes ; then let it cool 
to about 40° C. (104° F.), strain the liquid, and pass through the 
strainer enough cold water to make the product measure 1000 Cc. 

The use of cold water, to begin with, insures the complete extrac- 
tion from the drug of all its soluble principles, by the gradually 
heated water, the albuminous matter being subsequently coagulated 
as the heat is increased to near the boiling-point. If, on the 
other hand, the drug be at once immersed in boiling water, the 
albumen contained in cells would be coagulated, and thus seriously 
interfere with the extraction of the other constituents. In preparing 
compound decoctions, all the drugs may be added to the cold water, 
with the exception of those which, like senna, are injured by long- 



214 PRACTICAL PHARMACY. 

continued heat, or which contain aromatic or other volatile princi- 
ples ; such should be added when the decoction is ready to be 
removed from the fire or steam-bath, and allowed to digest until it 
is sufficiently cooled for straining. The material should in all cases 
be cut or braised, the degree of fineness depending upon the nature 
of the tissue Woody drugs may be reduced to a moderately fine 
powder; leaves, however, and other drugs consisting mainly of loose 
parenchyma, are better used in the form of a moderately coarse or 
very coarse powder. 

Unless the liquid is to be considerably boiled down, decoctions are 
best prepared in a vessel provided with a cover, which may be 
loosely put on until the boiling is completed, when the vessel should 
be well closed, particularly if additions have been made at the close 
of boiling. Porcelain is undoubtedly the best material for vessels 
used for preparing decoctions, since it is not acted upon by the 
various vegetable principles ; for similar reasons, glass flasks will 
answer a useful purpose in making small quantities of these prepa- 
rations. As a rule, it is best to avoid metallic vessels, except when 
made of block tin and used in connection with a steam bath. As 
many drugs contain tannin, vessels made of iron are not adapted for 
preparing their decoctions, and the usually imperfect covering of 
galvanized or tinned sheet iron renders the vessels lined with such 
material but little better suited for this purpose, aud still inferior to 
properly enamelled iron vessels. 

Asa rule, decoctions should be allowed to cool to below 40° C. (104° 
F.) before they are strained ; principles which are soluble only in 
hot water are then mostly precipitated, aud removed without, in most 
cases, weakening the medicinal effects of the preparations ; but, 
even with this precaution, the strained liquid may become unsightly 
in appearance by the further deposition, on cooling, of apotheme or 
matter soluble only in hot water. In such cases the pharmacist should 
be guided by the directions of the Pharmacopoeia or the inten- 
tions of the physician, and not sacrifice effect to elegance. 

Official Decoctions. 

Decoction of Cetraria is made by first macerating the cetraria 
with cold water, for half an hour, in order to remove a portion of the 
bitter principle present ; this liquid is rejected, after which the drug 
is boiled with fresh water, for half an hour. Each Cc. represents 
0.050 Gm. of cetraria. 

In compound decoction of Sarsaparilla, the sarsaparilla and guaia- 
cum wood are directed to be boiled with water, for half an hour, 
after which the sassafras, liquorice root, aud mezereum are added, 
and the whole is macerated without further heat in a well-covered 
vessel. Each Cc. represents 0.10 Gm. of sarsaparilla, 0.020 Gm. 
each of guaiacum wood, sassafras, and glycyrrhiza, and 0.010 Gm. 
of mezereum. 



DECOCTIONS AND INFUSIONS. 



215 



In the British Pharmacopoeia, thirteen decoctions are recognized, 
all of which are directed to be made with distilled water, and, in the 
majority of the formulas, boiling is continued for only ten minutes. 

The German Pharmacopoeia directs decoctions to be made of the 
strength of ten per cent, when not otherwise specified, by keeping the 
mixture of drug and cold water, for half an hour, in a bath of steam 
arising from boiling water, and then expressing while warm. Two 
preparations termed decoctions, of althsea and of flaxseed, are pre- 
pared cold by maceration for half an hour and subsequent gentle 
expression ; they belong more properly under the head of mucilages. 



Infusions. 

Infusions are aqueous solutions of the soluble principles of vege- 
table or animal drugs, obtained by maceration or digestion in hot 
or cold water, and differ from decoctions only in the lower degree of 
heat employed in their preparation. This process is particularly 
suitable for substances containing volatile or other principles which 
would be dissipated or injured by boiling. A convenient apparatus, 
well adapted for making these preparations, is Squire's infusion-pot, 
Fig. 201. This consists of the jar, A, with a projecting ledge near 

Fig. 201. 




Squire's infusion-pot. 



the top, which supports a strainer, b or d, containing the material 
to be exhausted ; the jar is closed by a well-fitting cover, c. The 
advantages of this contrivance are, that the material is exhausted by 
circulatory displacement — the liquid, as it becomes charged with the 
soluble ingredients, descending to the bottom, giving place to fresh 
portions of less saturated menstruum — and that no further straining 
is required if care has been taken not to use too fine a powder. 

Drugs are best adapted for exhaustion with water when cut into 
thin slices by a suitable knife, so that they may be easily permeated 
by the liquid ; if cutting be inadmissible, they should be bruised 
to a coarse powder. Ligneous drugs, however, should be in a fine 



216 PRACTICAL PHARMACY. 

or moderately fine powder, which is also best adapted for most of 
those infusions which may be made by percolation. 

Wherever possible, infusions should be made in porcelain or porce- 
lain-lined vessels, to avoid contact with metal. 

The U. S. Pharmacopoeia has adopted the plan of ordering all 
infusions, unless otherwise directed by the physician, with the excep- 
tion of four specially enumerated, to be made of 1 part of mate- 
rial to 20 parts of infusion, according to the following directions : 
"An ordinary infusion, the strength of which is not directed by the 
physician nor specified by the Pharmacopoeia, shall be prepared 
by the following formula : Take of the substance, coarsely com- 
minuted, 50 Gm.; boiling water, 1000 Co. ; water a sufficient quan- 
tity to make 1000 Cc. Put the substance into a suitable vessel 
provided with a cover, pour upon it the boiling water, cover the 
vessel tightly, and let it stand for one-half hour. Then strain, and 
pass enough water through the strainer to make the infusion measure 
1000 Cc. 

The Pharmacopoeia omits to direct the expression of the drug after 
infusion, but it is evident that bulky herbs and flowers, which are 
best adapted to this process, would retain a considerable proportion 
of the liquid, which cannot be washed out simply by passing water 
through the strainer to make up the deficiency in volume. 

Both in the cases of decoctions and infusions, the Pharmacopoeia 
requires that, when made of energetic or powerful substances, the 
physician shall specify the desired strength. 

Four infusions are officially recognized in the Pharmacopoeia, two 
prepared cold, by percolation, and two by maceration with hot water; 
the time directed for the latter method is not specified, maceration 
being continued until the liquid is cold. 

The strength of infusions of the German Pharmacopoeia is double 
that of our own, but the general directions given for their prepara- 
tion are nearly identical Avith the above, from which they differ only 
in this, that the mixture of drug and boiling water is heated for five 
minutes in a vapor bath of boiling water, occasionally stirred, 
allowed to cool, and strained. 



Official Infusions. 
Made by Percolation. 

Name. Strength. 

Infusum Cinchonse 
Infusum Pruni Virginians 4.0 Gm. of Wild Cherry in 100 Cc 



6.0 Gm. of Cinchona \ -r -. ™ ^ 

1.0 Cc. of Aromatic Sulphuric Acid 



Both infusions, if carefully prepared, are efficient preparations of 
the drugs from which they are made ; the former will contain all the 
alkaloids of cinchona, in solution as sulphates, and the latter, any 
hydrocyanic acid generated in the bark by the aid of water. 



DECOCTIONS AND INFUSIONS. 



217 



Made by Hot Maceration. 



Name 

Infnsura Digitalis 



Infusum Senna) Compositum 
(Black Draught) 



Strength. 
1.5 Gm. of Digitalis in 100 Cc. 
f 6.0 Gm. of Senna 
J 12.0 Gm. of Manna 
J 12.0 Gm. of Magnesium Sulphate 
[ 2.0 Gm. of Fennel 



In 100 Cc. 



Infusion of digitalis is pleasantly flavored with cinnamon water, 
and contains 10 per cent, by volume of alcohol, hence it will keep 
for a few days, particularly in a cool place. 



CHAPTEE XVI. 

SYBUPS. 

In pharmacy the term syrup is applied to concentrated solutions 
of sugar, the solvent being either water or an aqueous, acetous, or 
hydro-alcoholic solution of some medicinal or aromatic principle. 
The Pharmacopoeia applies the name syrupus or syrup to a nearly 
saturated solution of sugar in water; in practice this solution is 
usually termed simple syrup as a mark of distinction. Syrups are an 
old and favorite form of administering medicines, partly on account 
of the sweet taste, and partly because sugar is used as a preservative 
for otherwise unstable vegetable solutions, in place of alcohol, 
which is often contra-indicated in disease. The sugar used in mak- 
ing syrups should be of the best quality obtainable, as upon it 
depend the character and stability of the finished syrup. The 
Pharmacopoeia describes sugar as occurring in white, hard, crystalline 
granules, of purely sweet taste, which corresponds to the best com- 
mercial varieties known as granulated and cut loaf sugar ; in order 
to overcome the yellowish cast of sugar, refiners frequently add ultra- 
marine, Prussian blue, etc., which, to some extent, will pass even 
through paper filters and finally deposit in the syrup containers. 

Sugar is soluble in half its weight of water at 15° C. (59° F.), 
and a saturated solution thus prepared has the specific gravity 1.345; 
it is also soluble in 175 times its weight of official alcohol. Large 
quantities of sugar dissolved in water very materially increase the 
bulk of the liquid, a fact which must always be borne in mind in the 
preparation of syrups ; practically, two-thirds of the weight of sugar 
will equal its bulk in fluid measure, or, in other words, 750 Gm. of 
sugar when dissolved in water will increase its bulk about 500 Cc. 
The proper proportion of sugar to menstruum is of great importance, 
as upon it depends the stability of the syrup. Should the sugar 
be deficient in quantity, it could not efficiently protect the other 
organic principles in the syrup, and the latter would be liable to 
ferment. On the other hand, if too much sugar be dissolved by the 
aid of heat, the excess will crystallize after cooling and dispose an 
additional quantity to separate in like manner, thus leaving the 
syrup weaker in sugar than it should be and subject to similar 
alterations as if an insufficient quantity of sugar had been used. 

Preparation. In the preparation of syrups, solution of the sugar 
may be effected by one of the following methods : Agitation of sugar 
and solvent without heat, cold percolation of the sugar with the 
solvent, gentle heating of the sugar and solvent, or heating the mix- 



SYRUPS. 219 

ture of sugar and solvent to the boiling-point. The application of 
heat in the manufacture of syrups should be avoided as far as pos- 
sible, especially a boiling temperature, partly to prevent the loss of 
volatile constituents and partly to guard against any change in the 
character of the sugar, which, under the influence of heat and par- 
ticularly with acid liquids, is converted into inverted sugar, resel- 
ling glucose, and thereby predisposed to fermentation ; moreover, 
the use of heat, in open vessels, causes evaporation of a part of the 
solvent, which, if not restored, produces a supersaturated solution 
with the attending evil of crystallization referred to above. 

The preparation of syrups without heat is a feature of American 
pharmacy, both the British and German Pharmacopoeias directing 
the use of heat in every instance. By some authorities it is claimed 
that syrups made with heat are more permanent than those made 
cold ; this claim is not supported by experience in this country. 
For all syrups containing volatile principles or such as may be 
changed by heat, the cold process is positively advantageous, and if 
pure sugar be used, such syrups keep admirably. 

The process of cold percolation of sugar with the solvent was first 
suggested by L. Orinsky in 1871, and is now largely recommended 
in the Pharmacopoeia; the process is of decided advantage whenever 
the syrup is to be prepared without heat, although it requires a little 
care in its management so as to insure perfect solution and a clear 
percolate. A cylindrical, slightly tapering percolator is best adapted 
for the purpose. A clean soft piece of sponge is placed, with moderate 
pressure, in the neck of the percolator (if too tightly compressed 
the viscid liquid will not pass through, and if too loose the liquid 
passes too rapidily and not clear), upon it is poured the sugar in 
granular form and properly levelled and shaken down by tapping the 
sides of the percolator, after which a diaphragm of filter paper is 
laid on the surface and the solvent carefully poured on with the aid 
of a guiding rod. If the sponge or a tuft of absorbent cotton has 
been properly adjusted, the solution will be perfectly clear and trans- 
parent and pass out in drops only, all the sugar being taken up be- 
fore the end of the process ; but if the liquid passes too rapidly, or if 
it be turbid, it must be poured back into the percolator until the defect 
is remedied. Some objections have been made to this process, such as 
the time necessary for perfect solution of the sugar, and the fact that 
albuminous principles liable to induce fermentation are best removed 
by heat ; but it must be borne in mind that cold percolation requires 
very little attention after it has once been started, can be allowed to 
go on during the night, and does away with the necessity of subse- 
quent filtration ; the evil tendency of nitrogenized principles in the 
solvent may be overcome by the use of weak alcohol and glycerin, as 
is directed in many of the official formulas. 

In the case of some syrups, where the viscid character of the sol- 
vent precludes rapid solution of the sugar, or when the syrup is 
wanted in a hurry, a moderate heat may be employed to facilitate 



220 PRACTICAL PHARMACY. 

solution, by putting the sugar and solvent into a strong bottle one and a 
half times as large as the required volume of syrup, aud, after securely 
corking, keeping it in a heated water-bath at about 50° C. (122° F.), 
and frequently agitating until perfect solution is effected ; all loss of 
volatile principles is avoided by keeping the bottle well corked. 
Whenever the solvent contains latent ferments or a large proportion 
of albuminous matter, heating to the boiling-point is necessary, in 
order to render such principles harmless, as in the case of syrups pre- 
pared from fruit juices; but the heat should not be continued beyond 
the boiling-point, to avoid a change in the sugar. 

When large quantities of syrup are to be made with heat, the 
mixture of sugar and solvent is placed in a porcelain-lined or well- 
tinned kettle and heated over a direct fire or on a steam-bath, until 
the sugar is dissolved ; it is then strained and water added to make 
up the desired volume. 

Preservation. Syrups are best preserved in completely filled 
bottles, in a cool place, and will keep unaltered, if properly prepared, 
for a long time; the addition of preservatives, such as salicylic or 
boric acid, calcium sulphite, ether, etc., is unnecessary, and in fact, 
objectionable, and such syrups as cannot be kept with ordinary care 
should be made in small quantity only. When syrups have under- 
gone fermentation they are no longer fit for use, and even if the 
attempt be made to restore them by boiling, they are likely soon 
to spoil again, owing to the decreased proportion of sugar left in 
solution ; the best aud safest plan is to throw them away. Finished 
syrups should always be put into perfectly clean and dry bottles 
(if made so by heat, after they have become cold), so as to avoid 
dilution and possible contamination with fermentation germs, which 
are likely to lurk in imperfectly cleaned bottles. Bottles from 
which syrups have been dispensed should be thoroughly washed 
with weak lye and afterward with water, and then dried before they 
are refilled. 

All syrups, whether made by cold or hot process (except cold per- 
colation), require straining through flannel to remove particles of 
dust and dirt, and, in the case of colorless or light-colored syrups, 
their appearance will be greatly improved by filtering them, under 
cover, through paper or a pledget of cotton. 



The Official Syrups. 

The U. S. Pharmacopoeia recognizes thirty-two syrups, which may 
be conveniently divided into flavoring and medicated syrups; of 
these, twenty-five are directed to be made tuithout heat, three are 
raised to boiling heat, and in the remaining four the sugar is to be 
dissolved with a gentle heat. Of the twenty-five syrups made with- 
out heat, ten are merely mixtures of simple syrup and medicating 
liquids. 



SYRUPS. 221 

A. Flavoring Sybups. 

1. Syrupus. Official simple syrup contains 64.54 per cent, by 
weight of sugar, each Cc. representing 0.85 Gm.; it should be made 
with distilled water so as to produce a solution of crystalline clear- 
ness, and if heat be employed, the syrup should be passed through a 
small, dry strainer, which is then washed with sufficient distilled water 
used for rinsing the vessel, to bring the volume up to the required 
quantity. Simple syrup should be made and preserved with care. 
One pound measures very nearly twelve fluidounces. 

2. Syrupus Acidi Citrici. Syrup of citric acid is made by mixing 
spirit of lemon and a solution of citric acid with simple syrup; it is 
an excellent substitute for lemon syrup, being more stable and of 
uniform acidity. It is of pleasant flavor and slightly opalescent, 
each Cc. containing 010 Gm. of citric acid. Unfortunately syrup 
of citric acid, when kept on hand for some time, acquires a terebin- 
ihinate odor; it should therefore be made in small quantities. 

3. Syrupus Amygdala. Syrup of almond, or orgeat syrup, should 
always be made from blanched almonds, so as to be as free from 
color as possible ; blanching of almonds consists in macerating them 
in hot water until the yellow episperm, or skin, loosens and can be 
removed by pressing between the fingers. The blanched almonds 
are beaten into a smooth paste with sugar and water, to which syrup 
and orange-flower water are gradually added ; sugar is then dissolved 
in the strained liquid. Syrup of almond (also known in Europe as 
syrupus emulsivus) is whitish and opaque, and, when added to water 
yields a milk-like mixture ; it spoils readily unless kept in a cool 
place, in well-stoppered, completely-filled bottles. 

4. Syrupus Aurantii. Syrup of orange is made from a concen- 
trated tincture of the fresk, outer orange peel, which is mixed with 
calcium phosphate, sugar, and water, and then filtered ; the remainder 
of the sugar is dissolved in the filtrate. The finished product con- 
tains 10 per cent, of alcohol, and possesses an agreeable aroma. 
Syrup of orange should never be made by mixing fluid extract of 
orange peel with syrup, as practised by some pharmacists ; when 
so made it is more or less bitter, is without the fine orange flavor, 
and turns liquids containing iron preparations dark, on account of 
the tannin in the peel, which is not the case with the official syrup. 

5. Syrupus Aurantii Florum. Syrup of orange flowers contains 
the same proportion of sugar as simple syrup ; it is made without 
the aid of heat, most conveniently by percolation. 

6. Syrupus Rubi Idcei. Syrup of raspberry may be considered as 
a type of the class of fruit syrups, the official process of manufacture 
being equally applicable to strawberries, blackberries, currants, 
cherries, etc. The object of setting the crushed fruit aside at a 
moderate temperature, 20° to 25° C. (68° to 77° F.), for several 
days, is to insure the complete destruction of certain undesirable 
principles known as pectin, or vegetable jelly, which, if allowed to 



222 



PRACTICAL PHARMACY. 



Fig. 202. 



remain in the fruit juice, would cause the syrup to gelatinize and 
readily spoil. 

The complete removal of pectin is shown by the test with alcohol, 
as the filtered juice should mix clear with half its volume of the latter, 
which will not occur as long as pectin is present ; a concentrated 
solution of magnesium sulphate should also leave the filtered juice 
unaffected. 

The fermentation of fruit juices is usually conducted in casks or 
containers tightly closed but provided with a suitable means of 
escape for the carbon dioxide gas generated during the process, as 
shown in Fig. 202 ; the end of the fermentative process is indicated 

when gas-bubbles cease to escape 
through the water contained in 
the small bottle. Experience has 
shown that the addition of a small 
quantity of sugar (2 per cent, of 
the weight of the fruit) hastens 
fermentation, preserves the color, 
and facilitates subsequent filtra- 
tion of the juice. 

After removal of the pectin, 
the pulp is expressed and the 
juice allowed to subside in well- 
closed vessels, in a cool place, for 
two or three days until clear ; the 
supernatant liquid must be care- 
fully decanted or withdrawn and 
passed through a previously- 
wetted paper filter. Sugar should 
be added to the filtrate without 
delay and dissolved by stirring 
before the mixture is heated to 
boiling; any albuminous matter 
remaining in the juice is coagu- 
lated by heating and removed by 
subsequent straining. The mix- 
ture of filtered juice and sugar must not be boiled for any length of 
time, but the heat should be withdrawn when the syrup begins to 
boil quietly after the first frothing and rising of the liquid. 

7. Syrupus Tolutanus The official formula directs that a strong 
alcoholic solution of balsam of tolu be mixed with sugar and pre- 
cipitated calcium phosphate, the alcohol being subsequently evapor- 
ated spontaneously in a warm place ; the residue is triturated with 
cold water and filtered through paper, and to the filtrate, heated to 
about 60° C. (140 F.), the remainder of the sugar is added and 
dissolved by agitation. The short contact of cold water with the 
finely-divided balsam of tolu will scarcely dissolve much of the 
odorous principles, and the heating to 60° C. appears more appro- 




SYBUPS. 223 

priate before than after filtration of the mixture, as in the latter case 
it simply facilitates solution of the sugar, which is equally well 
accomplished in the cold. If all the alcohol be allowed to remain, 
as in the case of syrup of orange, and the aqueous mixture be set 
aside, with frequent agitation, for six or eight hours, before filtration, 
a much finer flavored syrup will be obtained, since the presence of 
5 per cent, of alcohol increases the solubility of the balsamic prin- 
ciples in the water. In case the alcohol is retained, the water and 
sugar ordered in the official formula must be reduced correspondingly, 
to 450 Cc. and 800 Gm., respectively. 

8. Syrupus Zingiberis. According to the Pharmacopoeia, syrup of 
ginger should be prepared from fluid extract of ginger, by mixing 
this with precipitated calcium phosphate, evaporating the alcohol, 
mixing the residue with water, filtering, and dissolving sugar in the 
filtrate. This does not yield a syrup of decided ginger odor or 
taste, for the reason that the cold water fails to take up sufficient of 
the oleo- resinous principles remaining w T ith the calcium phosphate. A 
syrup of stronger aroma and pungency and better suited as a flavor- 
ing agent to disguise the unpleasant taste of saline and other medi- 
cines, may be obtained by the following modification of the official 
formula : Mix 20 Cc. of alcohol with 30 Cc. of fluid extract of 
ginger and incorporate 30 Gm. of precipitated calcium phosphate; 
gradually add 450 Cc. of water and set the mixture aside, with fre- 
quent agitation, for six or eight hours ; then filter and wash the filter 
with water so as to obtain 500 Cc. of filtrate, in w-hich dissolve 
800 Gm. of sugar, by agitation without heat. 

B. Medicated Syrups. 

1. Syrupus Acacice. This syrup is prepared by mixing 1 volume 
of mucilage of acacia with 3 volumes of simple syrup, and is pre- 
ferably made extemporaneously, ow T ing to its tendency to deteriorate 
unless kept in a cold place ; mucilage of acacia spoils more readily 
than a w 7 ell-made syrup, and it is, therefore, of prime importance that 
the mucilage be fresh. Each Cc. of the syrup represents 0.378 Gm. 
of acacia. 

2. Syrupus Acidi Hydriodici. Syrup of hydriodic acid is officially 
prepared by adding a freshly-made solution of hydriodic acid, con- 
taining potassium hypophosphite, to simple syrup ; it contains 1 per 
cent, by weight of absolute hydriodic acid, equal to about 0.013 Gm. 
in each Cc. The syrup when freshly made is colorless, and keeps 
well for some time if preserved in completely filled bottles, in a dark 
place ; gradually, iodine is liberated and the syrup becomes colored, 
and if more than pale straw-colored, it should be rejected. (For further 
remarks, see Iodine and its Compounds). 

3. Syrupus Allli. Syrup of garlic owes its value to an essential 
oil, present in the fresh bulbs in larger proportion than in the dry, 
and readily extracted by maceration with diluted acetic acid, as 



224 PRACTICAL PHARMACY. 

directed by the Pharmacopoeia. The sugar must be dissolved without 
heat, and contact with metals must be avoided. 

4. Syrupus Althcece. In the official process for this syrup the cut 
althaea is first washed with cold water to remove dust and foreign 
matter, and then macerated for one hour with cold water, to which 
about 8 per cent, of alcohol has been added as a preservative ; the 
mixture is frequently stirred, aud finally strained without expression. 
Cold water is preferable to warm water, as the latter produces a thick, 
ropy mucilage. After the sugar has been dissolved in the iu fusion, 
glycerin, to the amount of 10 per ceut. by volume of the desired 
finished product, is added to preserve the rather unstable syrup. It 
must be preserved in completely filled bottles, in a cool place. 

5. Syrupus Calcii Ladophosphatis. The first step iu the prepara- 
tion of this syrup is the solution of calcium carbonate iu lactic acid 
diluted with water, producing calcium lactate ; the addition of phos- 
phoric acid causes the precipitation of calcium phosphate, which 
will be redissolved by the lactic acid and excess of phosphoric acid 
present, upon the further addition of water. If the phosphoric acid 
be diluted with about twice its volume of water, before it is added 
to the solution of calcium lactate, less trouble will be experienced, 
and, instead of forming a dense magma, the calcium phosphate will 
redissolve as fast as formed. The acid liquid, after the addition of 
water, is filtered, and to the filtrate, orange flower water and sugar are 
added, and the whole theu shaken until dissolved. Each Cc. of the 
finished syrup represents 0.02584 Gm. of tri-calcium phosphate. 

6. Syrupus Calcis. Advantage is taken, in the preparation of this 
syrup, of the well-known fact that sugar largely increases the solu- 
bility of lime in water, and this solubility varies with the proportion 
of sugar to the water used ; according to Peligot, 100 parts of sugar 
contained in 250 parts of aqueous solution, will take up 26.5 parts of 
lime, while the same quantity of sugar in 2000 parts of solution 
takes up only 18 parts of lime. Choice lime should be used — as 
fiee from carbonate and other impurities as possible. The official 
syrup of lime is of uncertain strength, the Pharmacopoeia not having 
fixed a definite proportion, but, when freshly made, it contains prob- 
ably 0.032 Gm. of calcium oxide in every Cc. The direction to boil 
the lime, sugar, and water together for five minutes, is not essential, 
except to gain time, for cold maceration with frequent agitation will 
cause an equally large amount of lime to be dissolved; but longer 
time is necessary — possibly two or three days. Syrup of lime changes 
very rapidly upon exposure to air, and should, therefore, be kept in 
Avell-stoppered bottles. 

7. Syrupus Ferri Iodidi. Syrup of ferrous iodide is made by 
adding a hot, freshly-prepared solution of iodide of iron to simple 
syrup. The official syrup contains about 10 per cent, by weight of 
ferrous iodide, or about 0.134 Gm. in each Cc. ; it should be preserved 
in small, completely-filled bottles, in a place accessible to sunlight. 
On exposure to air, the color of the syrup slowly changes to yellow 



SYBUPS. 225 

and afterward to brown, the change of color proceeding from the 
exposed surface downward ; when such a change is noticed, exposure 
of the syrup to direct sunlight Avill restore the original color. (For 
further remarks, see the Official Preparations of Iron.) 

8. Syrupus Ferri, Quinince ei Strychnines Phosphatum. The prep- 
aration of this syrup presents no difficulties if the official directions 
be followed. An aqueous solution of soluble phosphate of iron is 
mixed with phosphoric acid, and in this acid liquid the alkaloids, 
quinine and strychnine, are dissolved ; the solution is filtered into 
glycerin and then mixed with simple syrup. Each Cc. of the syrup 
contains 0.030 Gm. of quinine, 0.020 Gm. of soluble phosphate of 
iron, and 0.002 Gm. of strychnine; the presence of 10 per cent, of 
glycerin favors the stability of the syrup, but a gradual darkening 
of the color cannot be avoided, although it may be retarded by 
keeping the syrup in completely-filled bottles, in a dark place. 

9. Syrupus Hypophosphitum. By this name the Pharmacopoeia 
recognizes a syrup of the hypophosphites of calcium, potassium, and 
sodium flavored with spirit of lemon ; it is prepared by making a 
solution of the three salts in water, acidulating the same with hypo- 
phosphorous acid, and in it dissolving the sugar by agitation. Each 
Cc. of the syrup contains 0.045 Gm. of calcium hypophosphite, 0.015 
Gm. each of potassium and sodium hypophosphites, and 0.002 Gm. 
of dilute hypophosphorous acid. 

10. Syrupus Hypophosphitum cum Ferro. This syrup is made by 
dissolving 10 Gm. each of ferrous lactate and potassium citrate in 
1000 Cc. of the preceding syrup ; it darkens considerably by age, 
and should therefore be freshly made when wanted. Ferrous lactate 
in the form of crystalline crusts is the best of the commercial varie- 
ties, and should alone be used in the preparation of this syrup. 

11. Syrupus Ipecacuanhas. Syrup of ipecac is made from the 
fluid extract of the drug, which is well shaken with a mixture of 
acetic acid and water, for the purpose of bringing the active principle 
(emetine) into aqueous solution and of rejecting those undesirable 
constituents which are apt to cause flocculi in the syrup; after filtra- 
tion, glycerin is added to the clear liquid, and then the sugar, after 
which the mixture is well shaken, until dissolved. Formerly, syrup 
of ipecac was likely to sour in warm weather, but this difficulty is 
now obviated by the presence of 10 per cent, of glycerin ; each Cc. 
represents 0.070 Gm. of ipecac. 

12. Syrupus Kramerice. This syrup is prepared by mixing fluid 
extract of krameria with simple syrup, in the proportion of 45 
volumes of the former to 55 volumes of the latter ; each Cc. rep- 
resents 0.45 Gm. of krameria. 

13. Syrupus Lactucarii. In the official process for this syrup, 
tincture of lactucarium is slowly incorporated with sugar and pre- 
cipitated calcium phosphate, after which water is added in small 
portions at a time ; the mixture is then filtered, and in the filtrate 
sugar is dissolved without heat. The object of this treatment is to 

15 



226 PRACTICAL PHARMACY. 

obtain a clear, transparent syrup, which can be attained if the tinc- 
ture has been properly prepared and freed from the caoutchouc-like 
constituent present in the drug. Each Cc. of the syrup represents 
the active virtues of 0.050 Gm. of lactucarinm. 

14. Syrupus Picis Liquidce. Tar always contains certain impuri- 
ties which are readily soluble in cold water, and these it is intended 
to remove in the process officially directed for the syrup. Sand is 
mixed with the tar, before the addition of cold water, in order to 
facilitate the washing, which is continued for twelve hours with 
frequent stirring. After decanting and rejecting the first liquid, 
boiling distilled water is added to the purified tar, and the mixture is 
well stirred during fifteen minutes, after which glycerin is added and 
maceration continued for twenty-four hours, during which time the 
soluble constituents of the tar are extracted ; sugar is dissolved in the 
clear liquid, which has been decanted and filtered, with the aid of a 
gentle heat. Each Cc. represents the virtues of 0.075 Gm. of tar. 

15. Syrupus Pruni Virginiance. Wild cherry is macerated for 
twenty-four hours with a mixture of one volume of glycerin and 
two volumes of water, during which time a peculiar reaction or fer- 
mentation goes on between certain constituents of the bark, resulting 
in the formation of hydrocyanic acid, and a volatile oil identical 
with oil of bitter almond. After maceration the drug is slowly per- 
colated to practical exhaustion, and in the percolate the sugar is dis- 
solved without heat. Enough menstruum should be added to the 
powdered drug to thoroughly moisten it, and the percolator kept 
tightly closed to prevent loss of the hydrocyanic acid ; a No. 20 
powder being rather coarse, the mixture must be very firmly packed, 
so that the drug may be slowly exhausted. The presence of 15 per 
cent, by volume of glycerin will prevent the fermentative changes 
frequently observed heretofore in the finished syrup, although at 
the same time it increases the extraction of tannin from the bark. 
The amount of hydrocyanic acid present in the syrup is a very uncer- 
tain quantity, nor does it remain coustant, owing to exposure and its 
volatile and unstable character. 

16. Syrupus Rhei. The official formula directs a solution of 
potassium carbonate to be added to fluid extract of rhubarb, prior 
to its admixture with simple syrup ; a small quantity of spirit of cin- 
namon is also added as a flavoring agent. The addition of an alkali 
prevents the separation of resinous matter, by retaining the same in 
solutiou, and thus a clear syrup is obtained. The use of water for 
solution of the potassium carbonate and the addition of 5 per cent, 
of glycerin appear quite unnecessary, since the alkali can be dis- 
solved in a part of the simple syrup, and syrup of rhubarb thus 
prepared keeps admirably well. Each Cc. represents 0.100 Gm. of 
rhubarb. 

17. Syrupus Rhei Aromaticus. Aromatic or spiced syrup of 
rhubarb is made, according to the Pharmacopoeia, by mixing 
15 volumes of the aromatic tincture of rhubarb with 85 volumes of 



SYRUPS. 227 

simple syrup ; the result is a cloudy syrup, owing to the suspension 
of partially precipitated resinous matter. If a perfectly clear syrup 
is desired, it may be obtained by adding a small proportion of 
borax, about J per cent., or 5 Gm. for every 1000 Cc. of finished 
syrup ; the borax should be dissolved in the tincture, before the 
addition of the syrup. 

18. Syrupus Rosce. This preparation is a simple mixture of 1 
volume of fluid extract of rose with 7 volumes of syrup. It has a 
beautiful red color and an agreeably astringent taste, and, although 
reckoned among the medicated syrups, is more frequently employed 
as a flavoring- agent for saline and other mixtures. 

19. Syrupus Rubi. The official syrup of blackberry is made by 
mixing 1 volume of fluid extract of blackberry bark with 3 volumes 
of syrup. It has a strongly astringent taste and is of a deep reddish- 
brown color. 

20. Syrupus Sarsaparillce Compositus. In the preparation of this 
syrup a mixture is first prepared of the fluid extracts of sarsaparilla, 
senna, and liquorice root, and a very small quantity of the oils of 
sassafras, anise, and gaultheria ; this mixture, after the addition of 
water, is well shaken and set aside for an hour to allow separation 
of inert, insoluble matter, after which it is filtered. Sugar is dis- 
solved in the filtrate, with the aid of only a gentle heat, to avoid loss 
of the volatile oils. The finished syrup contains very nearly 8 per 
cent, of alcohol derived from the fluid extracts, and therefore a less 
quantity of sugar than most other syrups. The present official 
formula differs from those formerly employed, in omitting guaiacum 
wood and pale rose petals. Each Cc. of the finished syrup represents 
0.200 Gm. of sarsaparilla, 0.015 Gm. each of senna and liquorice root, 
and a trace each of the oils of gaultheria, anise, and sassafras. 

21. Syrupus Scillce. Syrup of squill is prepared by dissolving 
sugar in vinegar of squill ; the latter contains considerable albumin- 
ous matter, which it is intended to remove by the official directions to 
boil and filter the liquid before the addition of the sugar. On account 
of the very acid character of the preparation, contact with metallic 
vessels should be avoided. Each Cc. represents the active virtues of 
0.045 Gm. of squill. 

22. Syrupus Scillce Compositus. Compound syrup of squill, also 
sold under the name of hive syrup, is made from the fluid extracts 
of squill aud senega, as follows : The two fluid extracts are mixed, 
evaporated on a water-bath to about half their bulk, and then 
mixed with water.; when cold, the liquid is intimately mixed with 
precipitated calcium phosphate and filtered, to remove pectin com- 
pounds and albuminous matter, which are otherwise likely to pass 
through the filter. If necessary, the liquid should be returned to 
the filter until it passes through perfectly clear. To the clear filtrate 
is added a definite quantity of tartar emetic, previously dissolved in 
hot water, and then the prescribed quantity of sugar, which is dis- 
solved without heat. Each Cc. of the syrup contains 0.002 Gm. of 



228 PRACTICAL PHARMACY. 

antimony and potassium tartrate and the active principles of 0.080 
Gm. each of squill and senega. 

23. Syrwpus Senegce. Syrup of senega is made by dissolving 
sugar in fluid extract of senega previously diluted with water. 
Senega is rich in pectin compounds, the separation of which, in 
liquid preparations of the drug, is avoided by the presence of alkalies. 
Fluid extract of senega contains 5 per cent, of ammonia water, and 
the Pharmacopoeia recommends a further addition of 2J- per cent., 
before diluting the fluid extract with water. The mixture is filtered 
after standing three or four hours, and in the clear filtrate the sugar 
is dissolved without heat. Each Cc. of the syrup represents 0.200 
Gm. of senega. 

There appears to be no objection to preparing the syrup as wanted, 
by mixing one volume of fluid extract of senega with four volumes 
of simple syrup, this mixture keeping equally as well as the former 
more tedious preparation. 

24. Syrupus Sennce. The official process for making syrup of 
senna consists in preparing a strong infusion of the leaves, mixing 
this with alcohol and oil of coriander, removing the precipitate by 
filtration, and in the filtrate dissolving the sugar without heat ; each 
Cc. represents the virtues of 0.250 Gm. of senna. 

Long-continued digestion of senna leaves at 60° C. (140° F.), as 
directed in the Pharmacopoeia, is of no advantage, as the cathartic 
principles can be extracted in less time, and long maceration brings 
an undesirable amount of gum into solution ; digestion for six or 
eight hours is no doubt sufficient when followed by expression and 
a further treatment of the dregs on the strainer by percolation with 
hot water. Solution of the sugar in the clear liquid is greatly facil- 
itated by placing a well-corked bottle, containing both, in a moder- 
erately warm Avater-bath and agitating frequently. The gummy 
matter is precipitated upon the addition of alcohol, and some time 
must be allowed for complete separation of the precipitate, other- 
wise subsequent filtration of the liquid will be difficult ; the clear 
liquid is decanted and the remainder filtered, the filter being washed 
with water. 



CHAPTER XVII. 

MUCILAGES, HOXEYS, AND GLYCERITES. 

Mucilages. 

The preparations recognized in the Pharmacopoeia under this 
name are viscid adhesive liquids formed by solution of mucilaginous 
principles in water ; with one exception they are unstable and readily 
undergo putrefactive changes in warm weather, hence they should 
be freshly prepared when wanted. The four official mucilages are 
those of acacia, sassafras pith, tragacanth, and elm. 

Mucilago Acacice. The Pharmacopoeia recommends that acacia 
be washed with cold w 7 ater before it is brought into solution, for 
the purpose of removing foreign matter often adhering to the outer 
surface. The official formula w r ill produce quite a viscid liquid con- 
taining 34 per cent, of acacia, each Cc. representing 0.378 Gm. 
Owing to the fact that the solution of acacia becomes denser as it 
progresses, stirring or agitation of the mixture will be found some- 
what difficult toward the end of the process, and solution can be 
more readily effected by what is known as circulatory displacement 
(see page 114), that is, the suspension of the washed acacia in the 
water, in a bag of loosely textured cloth, to be occasionally moved 
about in the liquid so that fresh portions of the water may continu- 
ally displace the solution formed, and thus complete solution be 
more rapidly effected. Pieces of clear, white acacia should be 
selected for the mucilage, which, when made, should be preserved in 
completely filled bottles, in a cool place. 

Mucilago Sassafras Medullce. Mucilage of sassafras pith is made 
by macerating the pith in cold water for three hours and then strain- 
ing ; the mixture should be kept in a covered vessel and occasionally 
stirred with a glass rod. Each Cc. represents 0.02 Gra. of sassafras 
pith. 

Mucilago Tragacanthce. The official directions for preparing mucilage 
of tragacanth are, to add the tragacanth to a boiling mixture of glycerin 
aud water and then macerate for twenty-four hours, with frequent 
stirring; after the addition of more water, the mass is beaten to a 
uniform consistence and then forcibly expressed through muslin. 
Mucilage of tragacanth forms a somewhat opaque semi-liquid jelly 
containing 6 per cent, of tragacanth; the presence of 18 per cent, of 
glycerin prevents decomposition. Tragacanth is only partially soluble 
in water, but absorbs the latter and swells to a gelatin oid mass. 

Mucilago Ulmi. Mucilage of elm, although still recognized in 



230 PRACTICAL PHARMACY. 

the Pharmacopoeia, is bat very rarely prepared by pharmacists ; the 
official directions are to add 6 Gm. of braised elm to 100 Cc. of 
water and digest for one hour, in a covered vessel, on a water-bath. 
Mucilage of elm, like that of sassafras pith, spoils very readily, and 
should be freshly made when wanted. 

Honeys. 

Clarified honey, or Mel Despumatum of the Pharmacopoeia, is pre- 
pared by mixing honey with 2 per cent, of its weight of paper-pulp 
and heating the mixture on a water-bath as long as any scum rises to 
the surface; the scum is carefully removed with a skimmer and suf- 
ficient distilled water added to restore loss by evaporation, after which 
the mixture is strained and 5 per cent, of its weight of glycerin is 
added to the strained liquid, for the purpose of better preservation. 

Medicated honeys are simply mixtures of clarified honey with cer- 
tain medicinal agents, and are, as a rule, prepared extemporaneously. 

Only one medicated honey is recognized in the Pharmacopoeia, 
namely, Mel Kos?e, or honey of rose, which is made by mixing fluid 
extract of rose with clarified honey, in such proportion that the 
finished product shall contain the astringent virtues of 12 Gm. of 
rose petals iu every 100 Gm.; this is about equal to a mixture of 12 
Cc. of fluid extract of rose with 64 Cc. of clarified honey. 

Glycerites. 

This valuable class of preparations consists of solutions of the 
medicinal agents in glycerin; they are permanent and are readily 
miscible with water or alcohol. Of the official glycerites, five are 
liquid and one solid. 

Glyceritum Acidi Carbolici. This glycerite is conveniently pre- 
pared by placing crystallized carbolic acid and glycerin together in a 
porcelain dish and warming the mixture on a water-bath until per- 
fect solution is effected ; each Gm. of the finished glycerite represents 
0.20 Gm. of carbolic acid, which is equal to about 110 grains in one 
fluidounce. 

Glyeeritum Acidi Tannici. Although tannin is perfectly soluble 
in cold glycerin, the solution of so large a proportion as directed 
in the official glycerite is best effected by the aid of heat; contact 
with metallic vessels must be carefully avoided, and the tannin and 
glycerin should be intimately mixed with a glass rod before heat is 
applied. When solution is completed, a deep green, transparent 
liquid results, which should be strained, while still warm, through 
flannel or a pledget of cotton. Glycerite of tannin contains 20 per 
cent, of tannin, or about 0.300 Gm. in each Cc, which is equal to 
about 120 grains in one fluidounce. 

Glyceritum Amyli. The official directions for preparing glycerite 
of starch are to stir 10 parts of starch with 10 parts of water and 



MUCILAGES, HONEYS, AND GLYCERITES. 231 

80 parts of glycerin, to a homogeneous mixture, and then apply a 
gradually increased heat until a translucent jelly is formed. As 
starch usually occurs in lumps, it is necessary to first rub it, in a 
mortar, into a fine powder, which should be transferred to a porcelain 
capsule, and then mixed with the water and glycerin, so as to avoid 
loss, which is unavoidable if the mixture be made in the mor- 
tar; heat must be applied cautiously and the mixture constantly 
stirred with a thick glass rod or a wooden spatula, to avoid scorching 
and consequent discoloration. The liquid gradually thickens as the 
heat is increased, and the entire disappearance of white spots indi- 
cates perfect solution. The high heat indicated in the official for- 
mula is necessary to effect the rupture of the starch granules, without 
which solution of the starch cannot take place; to insure uniform 
heating, wire gauze should invariably be interposed between the 
capsule and the flame. Glycerite of starch is hygroscopic, therefore 
it must be preserved in tightly closed jars, so as to avoid contact 
with air. 

Glyceritum Boroglycerini. The preparation of this glycerite involves 
first the production of boroglycerin, known also as boroglyceride or 
glyceryl borate, and secondly, the solution of this compound in glycerin. 
When boric acid and glycerin are heated together to about 150° C. 
(302° F.), chemical action sets in, water being given off, while a new 
compound, glyceryl borate, is formed, which upon cooling is obtained 
as a transparent, almost colorless and very hygroscopic mass; the mix- 
ture must be frequently stirred to break up the constantly forming film, 
and care must be observed that the heat prescribed be neither exceeded 
nor continued longer than necessary, so as to avoid a yellowish or 
brownish coloration. Thirty-one parts of boric acid and 46 parts of 
glycerin will unite to form 50 parts of glyceryl borate; hence in the 
official process the reaction is known to be complete when the 
weight of the mixture has been reduced to 500 Gm.; then, while still 
hot, an equal weight of glycerin is added and thoroughly incorporated, 
thus making a 50 per cent, solution of boroglycerin. Each Cc. con- 
tains about 0.683 Gm. of boroglycerin, which is equal to about 312 
grains in a fluidounce. 

Glyceritum Hydrastis. In the official process for glycerite of 
hydrastis, the finely powdered root is exhausted with alcohol by per- 
colation, the resulting tincture mixed with water and the alcohol 
removed by distillation, in order to precipitate the resinous matter ; 
after dilution of the residue with more water, the mixture is set aside 
for twenty-four hours and then filtered, the filter being washed with 
water. To the filtrate, an equal volume of glycerin is added and the 
whole thoroughly mixed. Each Cc. of the finished glycerite repre- 
sents 0.500 Gm. of hydrastis, or a fluidounce contains about 228 
grains. 

According to Prof. Lloyd, the best results will be obtained if the 
official directions be modified to the extent that the alcoholic tincture, 
without the addition of water, be concentrated to a syrupy consistence 



232 PRACTICAL PHARMACY. 

by distillation or otherwise, and then poured into ice-cold water 
equal in quantity to one-half the weight of drug used ; the soft, oily, 
resinous matter separates readily and can be removed by filtration 
after a few hours' rest. The nitrate must be brought to a volume of 
500 Cc. for every 1000 Gm. of drug operated upon, by washing the 
filter with cold water, after which the glycerin is added and the 
mixture shaken thoroughly. 

This glycerite is chiefly intended to furnish a fluid preparation of 
hydrastis which shall be miscible with water in all proportions with- 
out precipitation. 

Glyceritum Vitelli. Glycerite of yelk of egg, or glyconin, is a 
mixture of 45 parts of yelk of egg and 55 parts of glycerin, of 
about the consistence of honey, which will keep for a long time if pre- 
served in well -stoppered bottles, so as to prevent the absorption of 
moisture from the air. In order to obtain a satisfactory preparation, 
the yelk of egg should be carefully separated from the albumen, and 
the membrane enclosing the yelk then ruptured, so that only the 
pure yelk may be weighed ; the glycerin should be added gradually, 
with constant trituration. 



CHAPTER XVIII. 

ELIXIRS. 

The word "elixir" is said to be of an ancient origin, and derived, 
according to Dr. Charles Rice, from two Arabic words, pronounced 
al-ihsir ; the Arabic iksir comes from the Greek word f^pwv, mean- 
ing a dry powder, such as was used for dusting wounds. For a 
long time the word w r as applied by alchemists to the won- 
derful transformation powder used in the supposed conversion 
of base metals into silver and gold. Later on, the term was also 
applied to liquids, and used to designate certain compound tinctures, 
for which rare medicinal properties were claimed. In this latter 
sense the term elixir is still used to some extent in Continental 
Europe, and, as a rule, such preparations are characterized by an 
unpleasant taste. In modern American pharmacy the word has 
come to mean an entirely different class of preparations, the distin- 
guishing features of which are a pleasantly aromatic sweet taste, and 
the presence of alcohol varying in proportion from 20 to 25 per cent, 
by volume. Prior to 1865, only two elixirs of this kind were used 
to any extent in this country — namely, Elixir of calisaya and Elixir 
of ammonium valerianate; but through the efforts of enterprising 
manufacturers the list was rapidly augmented and reached its height 
between 1870 and 1875. A reaction, however, gradually set in, and 
at the present day many once-popular elixirs have fallen into disuse. 
There can be no doubt that a sweet, aromatic, and slightly alcoholic 
liquid forms a pleasant vehicle for many remedies, but the presence 
of 25 per cent, of alcohol may, in some instances, be positively in- 
jurious, and, moreover, the active ingredients are frequently present 
in such small quantities as to render the medicinal value of the 
preparation doubtful. 

The American Pharmaceutical Association, in order to secure 
uniformity in the composition of the many elixirs dispensed by 
pharmacists, has published a series of 86 formulas for elixirs, in the 
National Formulary. This book was issued in 1888, and a revised 
edition is shortly to appear. Another series, containing about 275 
formulas for elixirs and many valuable directions in manipulation, 
was published by J. U. Lloyd in 1892, under the title Elixirs and 
Flavoring Extracts. Many elixirs can be prepared extemporaneously 
by simple solution of the medicinal ingredient in the desired vehicle; 
as, for instance, the elixirs of the alkali bromides, citrates, salicylates, 
and hypophosphites, elixir of pyrophosphate of iron, elixir of gentian, 
both simple and ferrated, etc. 

It is often desirable to impart color to an elixir, but since not all 



234 PRACTICAL PHARMACY, 

coloring agents are equally well suited for acid and alkaline liquids, 
it becomes necessary to exercise proper discretion. For acid or 
neutral liquids the National Formulary recommends either the sim- 
ple or compound tincture of cudbear, the former for a bright-red and 
the latter for a brownish-red tint ; of either tincture, two fluidrachms 
will suffice to color a pint of elixir. For alkaline liquids, such as 
elixir of ammonium valerianate, the coloring agent should be a solu- 
tion of carmine, which is best prepared with the aid of ammonia 
water; the National Formulary furnishes a satisfactory formula for 
the same. 

The Pharmaccepia recognizes only two elixirs — namely, aromatic 
elixir and elixir of phosphorus ; the former is simply a convenient 
vehicle or base for the preparation of many other elixirs, and has 
the following volume percentage composition : volatile oils, 0.33 
per cent.; deodorized alcohol, 24.67 per cent,; syrup and distilled 
water, each 37.5 per cent. On account of the turbidity caused by 
the solution of the oils when mixed with the aqueous liquid, the 
addition of precipitated calcium phosphate becomes necessary ; if the 
mixture be then well shaken, a clear filtrate can at once be obtained. 

Elixir of phosphorus contains 0.00025 Gm. of phosphorus in each 
Cc, and also 55 per cent, by volume of glycerin ; since phosphorus 
is very readily oxidized, the elixir should not be made in large 
quantities, and should be preserved in well-filled, tightly-stoppered, 
dark bottles. By following the pharmacopoeial directions exactly, a 
clear solution can readily be made. 

Composition of Official Elixirs. 

Name. Composition. 

f Compound Spirit of Orange 12 Cc. 

t-.,. . . ,. ! Deodorized Alcohol . . 238 " 
Elixir Aromaticum . . j g 375 « 

[ Distilled Water '. . . 375 " 
f Spirit of Phosphorus . . 210 Cc. 

™. • ni i . I Oil of Anise . . . 2 " 

Elixir Phosphon . . . -j Glycerin . . . . 550 « 

L Aromatic Elixir . . 238 '' 

It is not within the scope of this work to furnish numerous form- 
ulas for elixirs, but there are two elixirs which are deserving of 
special consideration, because they have been the source of much 
vexation to pharmacists ; these are the elixir of the phosphates of 
iron, quinine, and strychnine, and the elixir of pepsin, bismuth, and 
strychnine. 

Elixir Ferri, Quininoe et Strychnince Phosphatum. While this prep- 
aration was originally intended to be an elixir of the three phosphates, 
very few manufacturers make this claim for their preparation, and the 
published formulas simply direct the use of phosphate of iron with 
the pure alkaloids, or the sulphates or hydrochlorides, of quinine and 
strychnine. Some of the commercial elixirs of the above name form 
clear mixtures with water ; hence numerous efforts have been made 
to prepare an elixir which shall be permanent at all temperatures, 



ELIXIRS. 235 

and miscible with water in all proportions. Want of uniformity in 
strength is another unfortunate feature in the many elixirs of phos- 
phate of iron, quinine, and strychnine dispensed by pharmacists ; some 
contain twice as much iron and quinine as others, and the amount 
of strychnine varies still more. 

As a rule, the elixirs of phosphate of iron, quinine, and strychnine 
prescribed by physicians and offered for sale by manufacturers are 
supposed to be of one-half the strength of Easton's syrup, and to 
contain in each fluidrachm 1 grain of phosphate of iron, J grain of 
phosphate of quinine and -^ grain of phosphate of strychnine. This 
strength has also recently (1894) been adopted by the American 
Pharmaceutical Association, although the formula of the new Na- 
tional Formulary (revised edition) will direct- the quinine and strych- 
nine to be held in solution as alkaloids, and not as phosphates. Some 
of the elixirs of phosphate of iron, quinine, and strychnine, made 
with pure alkaloids, form turbid mixtures with small quantities of 
water (1 or 2 volumes), but become perfectly clear if more water be 
added (8 volumes); this is particularly the case with those containing 
an additional amount of simple syrup or some glycerin. Of the 
various formulas in use for this class, the following furnishes a very 
satisfactory light-colored (vellowish-green) preparation : 

Take of 

Soluble Phosphate of Iron (TJ.S.P.) . . .128 grains. 

Quinine, alkaloid ....... 64 " 

Strychnine, alkaloid ...... 2 " 

Alcohol 2 fiuidounces. 

Simple Svrup 2 " 

Distilled " Water 2 " 

Aromatic Elixir, sufficient to make ... 16 " 

Dissolve the alkaloids in the alcohol, add the syrup, and then 8 
fiuidounces of aromatic elixir. Dissolve the iron salt in the distilled 
water, by aid of a gentle heat (neutralizing the solution with am- 
monia, if necessary), mix with the alkaloidal solution, aud add suf- 
ficient aromatic elixir to bring the total volume up to 16 fiuidounces. 

If an elixir is desired containing the quinine aud strychnine as 
phosphates, in perfect solution with the phosphate of iron, and yet 
not unpleasantly acid (for a large excess of phosphoric acid will 
accomplish the purpose), some other substance must be added which 
shall prevent precipitation. After numerous experiments I have 
found ammonium acetate to produce the best results aud to yield an 
elixir which, even if made of double the stated strength, remains 
clear at a freezing temperature and mixes clear with water in all 
proportions. The very small proportion of ammonium acetate re- 
quired is not in any way hurtful, and need not be considered any 
more than the alkali citrate in the soluble phosphate of iron. 

All elixirs containing soluble phosphate of iron will darken mate- 
rially if exposed to light, and particularly that made by the following 
formula : hence they should be preserved and dispensed in amber- 
colored bottles. 



236 PRACTICAL PHARMACY. 

Take of 

Soluble Phosphate of Iron (U.S.P.). . . . 128 grains. 

Quinine, alkaloid 64 " 

Strychnine, alkaloid . . . . . . 2 " 

Phosphoric acid. 85 per cent . . . . .15 minims. 

Acetic Acid, 36 per cent. ..... 225 grains. 

Ammonium Carbonate . . . . . 71 " 

Alcohol 1 fluidounce. 

Distilled Water 1 of each a sufficient quantity to 1 -, P a . -, 
Aromatic Elixir} make . . ! . .} 16 fluidounces. 

Dissolve the quinine and strychnine in the alcohol, add 6 fluid- 
ounces of aromatic elixir, and then the phosphoric acid. Add the 
ammonium carbonate to the acetic acid contained in a beaker or 
graduate, and when the solution is complete, add enough distilled 
water to bring the volume up to 6 fluidrachms. Mix the ammo- 
nium acetate solution with the solution of quinine and strychnine 
phosphates, and add enough aromatic elixir to make the liquid meas- 
ure 14 fluidounces. Dissolve the iron scale salt in J fluidounce of 
distilled water by the aid of a gentle heat, and if the solution be 
acid to test-paper, neutralize exactly with ammonia water, and add 
enough aromatic elixir to bring the volume up to 2 fluidounces. 
Finally mix the two solutions. 

This preparation conforms in strength to that claimed for the ma- 
jority of the elixirs offered on the market, containing, in each fluid- 
drachm, 1 grain of phosphate of iron, and J grain of quinine and -g 1 ^ 
grain of strychnine, both in combination with phosphoric acid. If 
an elixir of twice the strength be desired, it can be readily obtained 
by doubling all the ingredients except the aromatic elixir. 

With some samples of soluble phosphate of iron, a slightly increased 
quantity of the ammonium acetate solution may be necessary, possi- 
bly owing to a loss of water and consequent relative increase of the 
proportion of the iron salt. 

Elixir Pepsini, Bismuthi et Strychnines. One of the chief difficulties 
in connection with this elixir has been the preparation of a neutral 
liquid which shall permanently retain all three of the active ingre- 
dients in solution. Pepsin is active only in acid fluids, and its action 
is inhibited, and in the course of time destroyed, by alkalies. The 
official bismuth and ammonium citrate is not a very stable com- 
pound, and although perfectly soluble when freshly prepared, in 
plain water, it loses this property in time, owing to decomposition of 
the ammonium citrate ; in alkaline liquids it retains its solubility, 
but an alkaline fluid will not only interfere with the pepsin, but may 
also throw the strychnine out of solution. The best that has been 
accomplished thus far has been a neutral solution of these three 
active ingredients — of doubtful stability, however, and likely to lose 
the bismuth salt by precipitation. 

Since physicians desire and extensively prescribe the elixir of 
pepsin, bismuth, and strychnine, it becomes the duty of the phar- 
macist to so prepare it that a permanent solution shall result; 
this can only be done with a liquid of acid reaction. In 1888, the 



ELIXIRS. 237 

late R. Kother called attention to a permanent solution of bismuth 
and sodium tartrate of acid reaction, and suggested its use in place 
of the bismuth and ammonium citrate. I would recommend the fol- 
lowing formula, which I have found to yield an unexceptionable 
preparation : 
Take of 

Pepsin in scales (U.S.P. standard | . . . .64 grains. 

Strychnine ........ 2 " 

Tartaric Acid ........ 2 " 

Distilled Water 4 fluidounces. 

Glycerin 2 " 

(rlycerite of Bismuth and Sodium Tartrate . .2 " 

Caramel ....... . . 4 drops. 

Aromatic Elixir . ...... 8 fluidounces. 

1. Dissolve the pepsin in a mixture of 1 fluidounce each of glycerin 
and water. 2. Dissolve the strychnine with the tartaric acid in 2J 
fluidounces of water, and add the balance of the glycerin, the bis- 
muth solution, the caramel, and the aromatic elixir. 3. Finally, pour 
the pepsin solutioD into the other liquid. In place of the pepsin a 
corresponding quantity of glycerite of pepsin, free from mineral acid, 
may be used, and in that case the water and glycerin must be reduced 
accordingly. 

This preparation coDtaiDS J grain of official pure pepsin, 2 grains 
of bismuth and sodium tartrate, and -^ grain of strychnine, in each 
fluidrachm. 

The glycerite of bismuth and sodium tartrate referred to in the 
above formula can be prepared as follows : 

Take of 

Bismuth Subnitrate 1142 grains. 

Nitric Acid . . . . . . . .19 fluidrachrns 

Tartaric Acid . . . . . . . . 1720 grains. 

Sodium bicarbonate . . . . . . . 1954 " 

Glycerin ......... 8 fluidounces. 

Instilled Water ...... a sufficient quantity. 

Dissolve the bismuth salt in the nitric acid previously diluted with 
10 fluidrachms of water; to the solution, slowly add 16 fluidounces 
of water. Now add 860 grains of powdered tartaric acid, and then, 
gradually, 977 grains of sodium bicarbonate. Dilute the magma of 
bismuth tartrate with 32 fluidounces of water. Set the mixture 
aside for five or six hours and wash by decautation and repeated 
affusion of water, until all nitric acid has been removed; drain the 
precipitate on a paper filter. Mix 977 grains of sodium bicarbonate 
with 5 fluidounces of water and gradually add 860 grains of pow- 
dered tartaric acid, warming slightly to obtain a perfect solution. 
Transfer the precipitate of bismuth tartrate to the solution of sodium 
tartrate and stir until dissolved; filter the solution, add the glycerin, 
and evaporate it on a water-bath, or dilute it with water, as may be 
necessary, so that the liquid shall measure 16 fluidounces. Each 
fluidrachm of this solution contains 16 grains of bismuth and sodium 
tartrate with an excess of sodium tartrate. 



CHAPTEE XIX. 



SPIRITS OR ESSENCES. 



In the Pharmacopoeia, the term "spiritus" is used to designate an 
alcoholic solution of volatile substances, chiefly volatile oils; in a few 
cases, water also is added. Of the twenty-five spirits recognized in 
the Pharmacopoeia, all but five can be conveniently prepared by the 
pharmacist, as they are quickly made and require only the ordinary 
apparatus usually found in the store; as a rule, they are pre- 
pared by simple solution of the liquid or gaseous body in alcohol, 
although sometimes distillation is resorted to. Whenever volatile 
oils, are used in the preparation of spirits, only the 'very best should 
be selected, as the value of the finished product depends entirely 
upon the quality of the oil ; particular attention should be paid to 
those oils likely to have assumed a terebinthinate odor, such as the 
oils of juniper, lemon, nutmeg, and orange peel. 

The following is a list of the official spirits, together with their 
composition : 



Official name. 



Spiritus iEtheris . 

Spiritus iEtheris Compositus 

(Hoffman's Anodyne). 
Spiritus iEtheris Mtrosi 



Spiritus Ammonias 

Spiritus Ammonias Aromaticus 



Spiritus Amygdalae Amarse (Eg 
sence of Bitter Almond). 

Spiritus Anisi 

Spiritus Aurantii . 

Spiritus Aurantii Compositus 

Spiritus Camphorae 

Spiritus Chloroformi 
Spiritus Cinnamomi 



Composition. 

Ether 1 volume, Alcohol 3 volumes. 

Ethereal Oil 1 volume, Ether 13 volumes 
Alcohol 26 volumes 

An alcoholic solution of Ethyl Nitrite, con- 
taining, when freshly made, between 4 and 5 
per cent, of the ethereal liquid. 

An alcoholic solution of Ammonia containing 
10 per cent, by weight of the gas. 

A hydro-alcoholic solution of normal Ammo- 
nium Carbonate, containing 70 per cent, by 
volume of Alcohol, 1 per cent, of Oil of 
Lemon, and yV per cent, each of Oil of 
Nutmeg and Oil of Lavender Flowers 

Oil of Bitter Almond 1 volume, Alcohol 80 
volumes, and Distilled Water sufficient to 
make 100 volumes 

Oil of Anise 1 volume, Deodorized Alcohol 9 
volumes. 

Oil of Orange Peel 1 volume, Deodorized Alco- 
hol 19 volumes 

Oil of Orange Peel 20 volumes, Oil of Lemon 
5 volumes, Oil of Coriander 2 volumes, Oil 
of Anise \ volume, Deodorized Alcohol 72<j 
volumes. 

Camphor 10 Gm., Alcohol sufficient to make 
100 Cc of solution. 

Chloroform 6 volumes, Alcohol 94 volumes. 

Oil of Cinnamon 1 volume, Alcohol 9 volumes. 



SPIRITS OR ESSENCES. 



239 



Spiritus Frurnenti (Whiskey 



Spiritus Gaultheriae 
Spiritus Glonoini (Spirit of Nitro- 
glycerin). 

Spiritus Juniperi . 

Spiritus Juniperi Compositus 



Spiritus Lavandulae 

Spiritus Limonis (Essence of 
Lemon). 



Spiritus Menth se Piperita? (Essence 
of Peppermint). 

Spiritus Mentha? Yiridis (Essence 
of Spearmint). 

Spiritus Myrciae (Bay Kum) . 



Spiritus Myristicae (Essence of 
Nutmeg). 

Spiritus Phosphori (Tincture of 

Phosphorus). 
Spiritus Vini Gallici (Brandy) 



An alcoholic liquid obtained by the distillation 
of the mash of fermented grain (usually of 
mixtures of corn, wheat, and rye), and at 
least two years old. 

Oil of Gaultheria 1 volume, Alcohol 19 volumes 

An alcoholic solution of Glonoin, or Nitrogly- 
cerin, containing 1 per cent, by weight of the 
substance. 

Oil of Juniper 1 volume, Alcohol 19 volumes. 

Oil of Juniper 8 volumes, Oil of Caraway and 
Oil of Fennel each 1 volume, Alcohol 1400 
volumes, Water sufficient to make 2000 vols. 

Oil of Lavender Flowers 1 volume, Deodor- 
ized Alcohol 19 volumes 

A 5 per cent, alcoholic solution of Oil of 
Lemon ; this spirit also contains in each liter 
the oil and coloring matter from 50 Gm of 
freshly grated lemon peel. 

Oil of Peppermint 1 volume, Alcohol 9 vols ; 
this spirit is colored green by peppermint 
herb. 

Oil of Spearmint 1 volume, Alcohol 9 volumes; 
this spirit is colored green by spearmint 
herb 

Oil of Myrcia 16 volumes, Oil of Orange Peel 
1 volume, Oil of Pimenta 1 volume Alcohol 
1220 volumes, Water sufficient to make 2000 
volumes. 

Oil of N utmeg 1 volume, Alcohol 19 volumes. 

A solution of Phosphorus in Absolute Alcohol 
representing 0.0012 Gm. in each Cc. 

An alcoholic liquid obtained by the distillation 
of the fermented unmodified juice of fresh 
grapes, and at least 4 years old. 



Special Remarks on Some Official Spirits. 

Sjnritus JEtheris Compositus. Commercial Hoffmann's anodyne 
varies greatly in composition, and is probably never identical with 
the official spirit — in fact, manufacturers do not claim this to be the 
case; hence the necessity for discrimination between the two prepa- 
rations when physicians prescribe compound spirit of ether. The 
commercial varieties of Hoffmann's anodyne are often obtained as 
by-products in the rectification of ether, and consist of mixtures of 
heavy and light oil of wine, ether, alcohol, and water, brought up to 
a certain arbitrary standard, varying with different manufacturers. 

Spirit JEtheris Xitrosi. This preparation is a very unstable solution, 
at least as far as the proportion of active ingredients is concerned ; 
even under the most favorable conditions it deteriorates; to retard this 
change, as far as possible, the spirit should be preserved in small, 
well-stoppered bottles, in a cool, dark place. Spirit of nitrous ether 
should be purchased in original packages, and never in bulk drawn 
from carboys. 

The chemical reactions involved in the manufacture of this spirit 
will be explained elsewhere, as also the official method of determining 
its quality. 



240 PRACTICAL PHARMACY. 

Spiritus Ammonice. The object of directing the use of alcohol 
recently distilled and preserved in glass, is to avoid discoloration of 
the liquid, which is apt to occur if ammonia gas be dissolved in alco- 
hol kept in barrels and containing organic impurities. Spirit of 
ammonia is of the same strength as official ammonia water, and is in- 
tended to be used in cases where the aqueous solutiou is inadmissible. 

Spiritus Ammonice Aromaticus. Ammonia water is used in connec- 
tion with official ammonium carbonate, for the purpose of converting 
the latter into the normal salt, as this alone is soluble in the alcoholic 
liquid ; in order to complete the change, it is advisable to let the aque- 
ous solution stand for twelve or twenty-four hours, before adding it 
to the mixture of oils and alcohol. Aromatic spirit of ammonia is 
of faint color when freshly prepared, but gradually becomes darker. 

Spiritus Frumenti. Whiskey, as recognized by the Pharmacopoeia, 
should contain from 50 to 58 per cent, by volume of alcohol, which 
is readily ascertained by aid of the alcoholometer described on page 
57. 100 Cc. of whiskey, when evaporated to dryness, should not 
yield more than 0.25 Gm. of residue. 

Spiritus Phosphori. The weighing of phosphorus requires consid- 
erable care, owing to its very inflammable nature; it should always 
be performed in water, and the phosphorus rapidly dried by means 
of filter-paper, before it is introduced into the absolute alcohol. The 
use of an upright condenser is necessary when heat is employed, 
to avoid ignition and loss of alcohol, which would occur in an 
unstoppered flask; agitation with cold absolute alcohol will also dis- 
solve phosphorus, but it is a tedious process. Phosphorus is far more 
soluble in fixed oils or chloroform, but since spirit of phosphorus is 
used chiefly in the preparation of elixir of phosphorus, such solutions 
would be inadmissible. Phosphorus is rapidly oxidized upon expos- 
ure to air, and particularly when in solution, hence the spirit must be 
preserved in small, securely stoppered vials, in a cool, dark place. 

Spiritus Villi Gallici. Official brandy should be at least four years 
old, and contain from 46 to 55 per cent, by volume of alcohol ; the 
older the brandy the finer is its quality. 100 Cc. of brandy, upon 
evaporation to dryness, should not yield more than 1.5 Gm. of residue. 



CHAPTER XX. 

TINCTURES. 

Tincture is the name applied to solutions of non-volatile or only 
partially volatile substances, in liquids other than simple water or 
glycerin, and which invariably contain alcohol; solutions of volatile 
substances in alcohol are always termed spirits or essences. While 
tinctures are usually assumed to be solutions of vegetable principles, 
this is not the case in all the official tinctures ; two of these, the 
tinctures of iodine and ferric chloride, are solutions of inorganic 
substances. Tincture of iodine is also an exception to the rule 
that tinctures are solutions of non-volatile substances. The men- 
struum or solvent used in the preparation of tinctures may be simply 
alcohol, various mixtures of alcohol and water, or of alcohol, 
glycerin, and water, ammoniated alcohol in the form of aromatic spirit 
of ammonia, and mixtures of alcohol and ether; according as these 
different menstrua are employed, tinctures are divided into groups 
designated as alcoholic, hydro- alcoholic, ammoniated, and ethereal 
tinctures respectively. Ethereal tinctures are not recognized in our 
Pharmacopoeia, but are employed to some extent in Europe. 

The Pharmacopoeia recognizes seventy-two tinctures, of which 
twenty are made with alcohol alone, fifty with a hydro-alcoholic men- 
struum, and two with ammoniated alcohol ; from this it is seen that 
the tendency is in the direction of weaker alcohol, and many tinctures 
formerly made with alcohol exclusively, are now found equally 
efficient and permanent when made with a mixture of alcohol and 
water. The valuable solvent and preservative properties of alcohol 
have been explained in a former chapter ; these are retained in the 
various hydro-alcoholic mixtures, in which the proportions of alcohol 
and water are so adjusted that complete extraction of the valuable 
constituents of the drug is insured as well as permanence of the 
solution ; the solution of much inert and unstable matter is likewise 
thus avoided. Tinctures made with weak alcohol are also more readily 
miscible with aqueous liquids — a point often of great value in dis- 
pensing medicines. The addition of glycerin to the menstruum is 
frequently desirable to facilitate the perfect extraction of astringent 
and other principles and prevent subsequent changes in the finished 
tincture, due to atmospheric influences, which cause the gelatinization 
of the solution or deposit of unsightly precipitates. 

Tinctures are, as a rule, prepared by percolatiou, except in the 
case of a few resins, balsams, gum-resins, and extractive drugs, for 
which maceration has proven more satisfactory. The process of per- 

16 



242 PRACTICAL PHARMACY. 

eolation has been fully described ou page 124 etseq., as well as the pre- 
cautions necessary to insure perfect extraction of drags. The great 
advantages to be derived from a proper moistening and preliminary 
maceration of the drug have been already pointed out in the chapter 
on Percolation. The value of this mode of solution cannot be over- 
estimated in the preparation of tinctures, and as the amount of 
available menstruum is ample, complete exhaustion of the drug will 
have been effected before all the solvent has passed through ; the 
objection urged that menstruum is retained by the marc, can be 
easily overcome (see page 129), and is but trifling as compared with 
the gain in time and in the perfect, clear solution at once obtained. 

Of the seventy-two official tinctures, fifty-six, or over three- fourths 
of the whole number, are directed to be made by percolation, eleven 
by maceration, four by direct solution, and one by decoction and 
subsequent concentration. In the pharmacopceial titles of tinctures, 
the names of the drugs furnishing the active ingredients are indi- 
cated in all but twelve ; of these, six are officially designated as 
compound tinctures, namely : the compound tinctures of benzoin, 
cardamom, catechu, cinchona, gentian, and lavender. In the remain- 
ing six titles, only the name of the chief ingredient is mentioned ; 
as tincture of aloes, tincture of cinnamon, camphorated tincture of 
opium, tincture of rhubarb, sweet tincture of rhubarb, and aromatic 
tincture of rhubarb. 

Upon exposure to air and light, tinctures, like all vegetable solu- 
tions, are apt to undergo change, and should, therefore, be kept in 
well-closed containers, in shady places ; extremes of temperature are 
equally hurtful on account of the possible change in the menstruum. 
Fortunately, the deposits formed in tinctures consist, as a rule, only 
of inert extractive matter, which may be removed by filtration. 

The following table shows at a glance the composition and strength 
of the official tinctures, as well as the fineness of powder and the 
menstruum used in their preparation. 



TINCTURES, 



243 



Table of Official Tinctures arranged Alphabetically 
Tinctures Made by Percolation. 













Quan- 














tity of 






Quantity of drug 


used for 


Fine- 




men- 
struum 

to 
moisten 


Degree of 


Official Name. 


1000 Cc. of tincture. 


ness of Menstruum. 


Packing. 








powder. 
















drug. 

200 Cc. 




Tinctura — 
Aconiti . . . 


Ac-unite 


350 Gm. 


No. 60 


J Alcohol 7 vols. ) 
i Water 3 " f 


Firm. 


Aloes .... 


• S Purified Aloes 
I Liquorice Root 


100 " 1 
200 " ( 


" 40 Dil. Alcohol 


80 " 


'« 


Aloes et Myrrha- 


( Purified Aloes 
•I Myrrh 
(Liquorice Root 


100 " ") 

ioo " y 

100 " j 


" j.n / Alcohol 3 vols, i 
w I Water 1 vol. $ 


60 " 


" 


Arnica? Florum 


Arnica Flowers 


200 ". 


" 20 Dil. Alcohol 





" 


Arnicas Radicis 


Arnica Root 


100 " 


" do [Alcohol 65 vols. ) 
w 1 Water 35 ' 


150 ". 


" 


Aurantii Amari 


Bitter Orange Peel 


200 " 

f 


" 30 
Cut in 


! Alcohol 6 " ( 
1 Water 4 " f 


200 " 


Moderate. 


Aurantii Dulcis 


Sweet Orange Peel 


200 " J 


small 


y Alcohol 


800 " 


" 






( 


pieces ) 






BelladonnaeFol. 


Belladonna Leaves 


150 " 


No. 60 Dil. Alcohol 


200 " 


Firm. 


Bryonia? . . 


Bryonia 


100 " 


" 40 


Alcohol 


100 " 


" 


Calendula? . . 


Calendula 


200 " 


" 20 


Alcohol 


200 «• 


" 


Calumba? . . Calumba 


100 " 


" 20 


/Alcohol 6 vols. 1 
I Water 4 " J 
Alcohol 


100 " 


" 


Cannabis Indica? Indian Cannabis 


150 " 


" 40 


150 " 


«< 


Cantbaridis 


Cantharides 


50 " 


" 60 


Alcohol 


30 " 


" 


Capsici . . . 


Capsicum 


50 " 


" 30 


f Alcohol 95 vols. \ 
(.Water b il \ 
Dil. Alcohol 


40 " 


" 


Cardamonii . . 


Cardamom 


100 " 


" 30 


100 " 


•< 




' Cardamom 


20 " "j 












Cassia Cinnamon 


20 " 










Cardamonii 
Composita 


Caraway 10 " 
• Cochineal 5 " 
(the finished product also con- 


" 40 


Dil. Alcohol 


25 " 






tains 5 per cent of 


glycerin, 












added after percolation) 










Catecbu 

Composita 


| Catechu 

i Cassia Cinnamon 


100 Gm. I 
50 " j 


" 40 


Dil. Alcohol 





(i 


Chirata? . . . 


Chirata 


100 " 


" 40 


J" Alcohol 65 vols. ) 
(Water 35 " } 


100 " 


" 


Ciniicifuga? . . 


Cimicifuga 


200 " 


" 60 


Alcohol 
(Alcohol 67. Svols.") 


150 " 


" 


Cinchona? . . 


Cinchona 


200 " 


" 60 


■i Water 25 " \- 

( Glycerin 7.5 " j 


200 " 


" 


Cinchona? 

Composita 


( Red Cinchona 


100 " •) 




(Alcohol 85 " | 






< Bitter Orange Peel 
( Serpentaria 


so " y 

20 « J 


" 60 


■I Water 7.5" V 
(Glycerin 7.5" J 


200 " 


" 










(Alcohol 75 " 1 






Cinnamomi . . 


Ceylon Cinnamon 


100 " 


" 40 


-j Water 20 " V 
(Glycerin 5 "J 


50 " 




Colchici'Seminis 


Colchicum Seed 


150 " '30 


J Alcohol 6 vols, i 
\ Water 4 " M 


100 " 


Moderate. 


Croci .... 


Saffron 


100 " 


Dil. Alcohol 


100 " 


Firm. 


Cubeba? . . . 


Cubeb 


200 " " 30 


Alcohol 


100 " 


'« 


Digitalis . . . 


Digitalis 


150 " ;< 60 


Dil. Alcohol 


150 " 


«< 


Galla? .... 


Nutgall 


200 " 


" 40 


f Alcohol 9 vols. 1 
(Glycerin 1 vol. J 





" 


Gelsemii . . . 


Gelsemiuni 


150 " 


" 60 


\ Alcohol 65 vols. ) 
| Water 35 " \\ 


100 " 


<< 


Gentiana? 

Composita 


(Gentian 

■< Bitter Orange Peel 
( Cardamom 


100 " -) 

40 " y 

10 " j 


" 40 


J Alcohol 6 " > 
I Water i " J 


100 " 


Firm. 


Humuli . . . 


Hops 


200 " 


" 20 


Dil. Alcohol 


400 " 


'* 


Hydrastis . . 


Hydrastis 


200 " 


" 60 


Dil. Alcohol 


150 " 


" 


Hyoscyami . . 


Hyoscyamus 


150 " 


" 60 


Dil. Alcohol 


150 " 


" 


Krameria? . . 


Krameria 


200 " 


«■ 40 


Dil. Alcohol 


200 " 


" 


Lactucarii . . 


f Lactucarium 

J (the drug is mixed 

j and treated twice 


500 " "] 
vith sand U 
with ben- f 




f Alcohol 50 vols. "I 

Water 20 " | 

■1 Glycerin 25 " [■ 

afterward 
(Dil. Alcohol | 





Moderate. 




( zin, before percolation) 









244 



PRACTICAL PHARMACY, 











Quan- 












tity of 






Quantity of drug used for 


Fine- 




men- 
struum 

to 
moisten 


Degree of 


Official Name. 


1000 Cc. of tincture. 


ness of 


Menstruum. 


Packing. 






powder. 








• 






drug. 






' Oil of Lavender Flowers 8 Cc. ~| 










Tinctura — 


Oil of Rosemary 2 " 




f Alcohol 70 vols." 






Lavandulae 


Cassia Cinnamon 20 Gm. [ 
Cloves 5 " f 


No. 20 


! Water 25 " 
afterward 




Firm. 


Composita 


Nutmeg 10 " 
Red Saunders 10 " J 




[Dil. Alcohol 
















Lobelia? . . . ~ Lobelia 200 " 


" 40 


Dil. Alcohol 


200 Cc. 


" 


Matico ... Matico 100 " 


" 40 


Dil. Alcohol 


100 " 


" 


Opii .... Powd. Opium 100 " 




Dil. Alcohol 










f 


Finished product 


Opii Deodorata Powd. Opium 100 " 




Water 1 


contains 20 per 
cent, of alcohol 


Physostigmatis Physostigma 150 " 


" 40 


Alcohol 


100 Cc. 


Firm. 


Pyrethri . . . Pyrethrum 200 " 


" 40 


Alcohol 


150 " 


" 


Quassiae ... Quassia 100 " 


" 40 


$ Alcohol 35 vols. ) 
} Water 65 " f 


100 " 


" 


„. . < Rhubarb 100 " ) 
Knei • • • ' \\ Cardamom 20 " $ 


" 40 


("Alcohol 6 " S 
■I Water 3 " V 
(Glycerin 1 vol. j 


100 " 


" 


[Rhubarb 200 " "] 
„, . . , . Cassia Cinnamon 40 '' 
Rhei Aromatica ^ cloveg 40 <( V 

[Nutmeg 20 " J 




f Alcohol 5 vols.") 
I Water 4 " 
■I Glycerin 1 vol. [ 
\ afterward 


100 " 


" 




[Dil. Alcohol 1 
f Alcohol 5 vols.' 
| Water 4 " 








'Rhubarb 100 " "1 








Rhei Dulcis . . 1 


Glycyrrhiza 40 " [ 
Anise 40 " | 
Cardamom 10 " J 


« 40 


■{ Glycerin 1 vol. ■ 

afterward 
| Dil. Alcohol 


150 " 








(Alcohol 6 vols." 1 






Sanguinariaj . Sanguinaria 150 " 


" 60 


^ Water 4 " 
I Acetic Acid 2 p c. 


100 " 




Scillas .... 


Squill 150 " 


" 30 


("Alcohol 3 vols. 1 
(Water 1 vol. j 


200 " 


€1 


Serpentarias 


Serpentaria 100 " 


" 40 


j Alcohol 65 vols. \ 
\ Water 35 " j 


; 100 " 


" 


Stramonii i 
Scminis s 


Stramonium Seed 150 " 


" 40 


Dil. Alcohol 


100 " 


" 


Strophanthi Strophanthus 50 " 


" 30 


(Alcohol 65 vols. ) 
'( Water 35 " f 


70 " 


.< 


Sumbul ... Sumbul 100 " 


•' 30 


(Alcohol 65 " 1 
1 Water 35 " i" 


100 " 


» 


Valerians* . . Valerian 200 " 


" 60 


(Alcohol 75 " \ 
1 Water 25 " J 


100 " 


" 


Valeriana 1 Yalerian 200 « 
Ammoniata J 


" 60 


J Aromatic Spirit \ 
1 of Ammonia j 


200 " 


(I 








j* Alcohol 65 vols. ) 
\ Water 35 " j 






Vanillte . . . 


Vanilla 100 " 








Veratri Viridis 


Veratrum Viride 400 " 


" 60 


Alcohol 


150 " 


" 


Zingiberis . . 


Ginger 200 " 


" 40 


Alcohol 


50 " 





Tinctures Made by Solution. 



Official Name. 


Quantity of drug used for 1000 Cc. of tincture. 


Menstruum. 


Tinctura — 

Ferri Chloridi .... 
Lpecacuanhse et Opii . 
Iodi . 


Solution of Ferric Chloride . . 250 Cc. 
( Fluid Extract of Ipecac . . .100 " ( 
\ Tincture of deodorized Opium . 1000 " f 

Iodine 70 Gm. 


Alcohol. 
Dil. alcohol. 
Alcohol. 


Nucis Vomicae . . 


Extract of Nux Vomica ... 20 " 


(Alcohol 750 Cc. 
| Water 250 " 



TINCTURES. 



245 





Tinctures Made by Maceration. 










Length of 


Official Name. 


Quantity of drug used for 1000 Cc. 


Menstruum. 


time of 




of tincture. 




maceration. 


Tinctura — 








Asafcetidse .... 


Asafetida, bruised 200 Gm. 


Alcohol 


7 days. 


Benzoini 


Benzoin, coarse powder 200 " 


" 


7 " 


Benzoini Composita . 


f Benzoin, " " 120 " ~| 
J Purified Aloes 20 " 
j Storax 80 " | 
[Balsam of Tolu 40 " J 


« 


C 2 hours ; 

digestion at 
-j a tempera- 
j tureof65°C. 
[ (149° F.) 


Herbarum Kecentium 


Fresh Herbs (bruised) 500 " 


" 


14 days. 


Guaiaci 


Guaiac, coarse powder 200 " 


" 


7 " 


Guaiaci Ammoniata . 


Guaiac, coarse powder 200 " 


f Aromatic Spirit of I 
( Ammonia j 
f Glycerin 150 Cc. ) 


7 " 


Kino 


Kino 100 " 


1 Water 200 " V- 
[Alcohol 650 " ) 


24 hours. 


Moschi 


Musk 50 " 


Dil. Alcohol 


7 days. 


Myrrhas 


(Myrrh, moderately coarse ") 
\ powder 200 " ( 
f Opium powdered 4 " "] 
I Benzoic Acid 4 " | 


Alcohol 


7 " 


Opii Camphorata . . 


■I Camphor 4 '' j* 

Oil of Anise 4 Cc. 
[Glycerin 40 " J 


Dil. Alcohol. 


o (( 


Tolutana 


Balsam of Tolu 100 Gm. 


Alcohol 


("Until dis- 
[ solved. 



Tincture Made by Decoction. 



Official Name. 


Quantity of drug used for 1000 Cc. 
of tincture. 


Menstruum . 


Tinctura Quillajae 


Quillaja, coarsely ground 200 Gm. 


( Boiling water ; the decoction is pre- 
< served by alcohol, of which the fin- 
[ ished tincture contains 35 per cent. 



The strength of the tinctures of the U. S. Pharmacopoeia varies 
from 1.6 to 50 Gm. of drug, being in the majority of cases 10, 15, or 
20 Gm. for every 100 Cc. of finished product, while the British Phar- 
macopoeia, as a rule, employs 2 j- oz. av. of the drug for each Imperial 
pint (20 fluidounces) of tincture, or 1 part of drug for 8 measured parts 
of fluid. The French and German Pharmacopoeias prepare their tinc- 
tures, almost without exception, of such strength that 1 part of drug is 
represented by about 5 or 10 parts of tincture by weight. While the 
difference in strength between our own and the British tinctures, is 
in the majority of cases, of no great importance, it is quite marked in 
a few tinctures, and should be borne in mind when filling British 
prescriptions; thus, our tincture of aconite is about 3 times as 
strong as the British tincture, our tincture of cantharides is 4 times 
as strong, our tincture of belladonna is 3 times as strong, our tincture 
of iodine nearly 3 times as strong, our tincture of opium J stronger, 
our tincture of mix vomica about 50 per cent, stronger, and our 
tincture of veratrum viride twice as strong. The following table 
represents a classification of the official tinctures based upon the 
amount of drug represented in each liter. 



246 



PRACTICAL PHARMACY. 



Table of Official Tinctures 
16 Gm. of Drug in 1000 Cc. 

50 Gm. of Drug in 1000 Cc. 

55 Gm. of Drug in 1000 Cc 
70 Gm. of Drug in 1000 Cc 



100 Gm. of Drug in 1000 Cc 



120 Gm. of Drug in 1000 Cc 
131 Gm of Drug in 1000 Cc 
(Calculated for anhydrous salt.) 



150 Gm. of Drug in 1000 Cc. 



200 Gm. of Drug in 1000 Cc. 



RRANGED 


ACCORDING TO STRENGTH 


Tinctura Opii Camphorata. 


r :: 

j 


Cantharidis. 


Capsici. 


1 


Moschi. 


L " 


Strophanthi. 


{ " 


Cardamomi Composita. 


Lavandulae. 


u 


Iodi. 


tt 


Arnica? Eadicis. 


It 


Bryonia. 


" 


Calumba?. 


tt 


Cardamomi. 


l( 


Chirata?. 


U 


Cinnamomi. 


a 


Croci. 


ct 


Kino. 


" 


Matico. 


tt 


Opii. 


it 


Opii Deodorata. 


tt 


Quassia?. ,._j 


a 


Serpentaria?. 


a 


Sumbul. 


it 


Tolutana. 


I " 


Vanilla?. 


tt 


Khei. 


u 


Ferri Chloridi. 


r " 


Belladonna? Foliorum. 


it 


Cannabis Indica?. 


a 


Catechu Composita. 


a 


Colchici Seminis. 


a 


Digitalis. 


it 


Gelsemii. 


« 
1 


Gentiana? Composita. 


I 


Hyoscyami. -^ 


it 


Physostigmatis. 


" 


Ehei Dulcis. 


a 


Sanguinaria?. 


" 


Scilla?. 


I " 


Stramonii Seminis 


tt 


Arnica? Florum. 


a 


Asafcetida?. 


a 


Aurantii Amari. 


11 


Aurantii Dulcis. 


it 


Benzoini. 


it 


Calendula?. 


it 


Cimicifuga?. 


a 


Cinchona?. 


u 


Cinchona? Composita. 


a 


Cubeba?. 


a 


Gallae. 


a 
J 


Guaiaci. 


1 tt 


Guaiaci Ammoniata. 


a 


Humuli. 


Cl 


Hydrastis 


it 


Ipecacuanha? et Opii. 


a 


Krameria?. 


it 


Lobelia?. 


a 


Myrrh a?. 


cc 


Pyrethri. 


cc 


Quillaja?. 


" 


Valerianae. 


tl 


Valeriana? Ammoniata. 


it 


Zingiberis. 



TINCTURES. 247 

260 Gm of Drug in 1000 Cc. Tinctura Benzoini Composita. 

" Aloes. 



300 Gm. of Drug in 1000 Cc. 4 " Aloes et Myrrhse. 

[ " Rhei Aromatica. 

350 Gm. of Drug in 1000 Cc. " Aconiti 

400 Gm. of Drug in 1000 Cc. " Veratri Viridis. 

500 Gm. of Drug in 1000 Cc. { [] ^erbaru* Eecentium. 

t Lactucarn. 

Special Remarks. 

Tinctura Aconiti. This important tincture requires care in its prep- 
aration, as the drug is not easily exhausted. The drug should be of 
prime quality, producing, when chewed, the characteristic tingling 
sensation in the tip end of the tongue, and the percolation should be 
conducted slowly at the rate of not over 10 drops per minute. The 
residue in the percolator must be devoid of all physiological effect. 

Fleming's tincture of aconite, which is still prescribed by some 
physicians, is very nearly twice as strong as the official tincture; it is 
made with alcohol, and 480 grains of aconite root are represented in 
lj- fluidounces of the tincture. 

Tinctura Aloes. The use of powdered liquorice root enables the 
tincture to be made by percolation, which otherwise would be impossi- 
ble ; the liquorice also modifies the bitter taste of the aloes consider- 
ably. The same remarks apply to the tincture of aloes and myrrh. 

Tinctura Arnicce Florum. The pharmacopceial direction to pack 
the powder dry, offers no advantage in the preparation of the tincture ; 
if the powder be moistened with about 1J times its weight of men- 
struum it can be more firmly compressed than when dry. 

Tinctura Asafoetidce. Select asafetida should be used, containing 
at least 60 per cent, of matter soluble in alcohol. It must be fre- 
quently agitated during maceration. 

Tinctura Aurantii Dulcis. Since the inner white layer of the 
orange peel contains tannin and is devoid of aroma, it should be 
carefully removed with a sharp knife, and only the yellow outer rind 
of the fresh peel be used, as officially directed ; this can be split into 
narrow strips and then cut into small pieces, or the rind may be care- 
fully grated. Maceration for five or six days, with frequent agitation, 
is advantageous, as packing of the pieces is performed with difficulty. 

Tinctura Benzoini Composita. This tincture is intended to take the 
place of numerous proprietary preparations, such as Wade's, Vervain's, 
Saint Victor's, Jesuits', Friar's, Turlington's, Persian and Swedish 
balsam. 

Tinctura Bryonice. The official directions to employ recently 
dried bryony root will be found difficult to follow, since bryony does 
not grow iu this country. Bryony is known to yield its active vir- 
tues to water ; diluted alcohol will, therefore, produce a tincture as 
efficient as one made according to the Pharmacopoeia, with alcohol. 

Tinctura Cannabis Indicce. The tincture of the British Pharma- 
copoeia is nearly three times as strong as our own, being made by dis- 



248 PRACTICAL PHARMACY. 

solving 1 oz. av. of the extract of Indian hemp in 20 fluidounces of 
alcohol. 

Tinctura Cinnamomi. The tendency to gelatinize, which has been 
observed in tincture of cinnamon when made with weak alcohol, has 
been overcome in the Pharmacopoeia by the use of a stronger alcoholic 
menstruum and the addition of glycerin. 

Tinctura Ferri Chloridi. When an acid solution of ferric chloride 
and alcohol are mixed, as in the official process, an ethereal odor is 
gradually developed, due to chemical actiou between the alcohol and 
the acid ; the pharmacopoeial direction, to allow the mixture to stand 
at least three months before using, is intended to insure uniformity 
by bringing all changes to completion. When exposed to light, the 
ferric chloride is, in part, reduced to the ferrous condition ; hence the 
necessity for protecting the tincture from light. 

Tinctura Gallce. Tincture of nutgall, when kept on hand for some 
time, undergoes change and deposits gallic acid ; the presence of 
glycerin retards such changes. 

Tinctura Herbarum Hecentium. Tinctures of fresh herbs can, of 
course, only be made from such plants as grow in this country, and 
must vary in quality according to the amount of moisture present in 
the drug ; the use of alcohol as a menstruum prevents the solution 
of mucilaginous and other inert matter and insures the presence of 
all valuable alcohol-soluble constituents, such as alkaloids, resins, 
volatile oils, etc. 

Tinctura Ipecacuanhce et Opii. This preparation may be regarded 
as a liquid form of Dover's powder, as it represents, in each Cc, the 
equivalent of 0.100 Gra. each of ipecac and opium. The concentra- 
tion of the tincture of deodorized opium is necessary for the intro- 
duction of the fluid extract of ipecac, the original volume being again 
restored by addition of diluted alcohol ; the precipitate formed con- 
sists of inert matter and is removed by filtration. 

Tinctura Kino. The tendency of this tincture to gelatinize can be 
entirely overcome by preserving it in a cool place, in well-stoppered 
1 oz. or 2 oz. vials, thus obviating frequent exposure to air. 

Tinctura Lactucarii. Lactucarium contains, besides the active bitter 
principles lactucin, lactucic acid, and lactucopicrin, an inert caoutchouc- 
like substance, lactucerin, which is removed by treatment with ben- 
zin, as directed in the Pharmacopoeia; the mixture must be filtered 
in a well-covered funnel and the dregs carefully washed with benzin. 
In order to get rid of all benzin odor, the residue should be dried in 
a current of warm air. The percolation of the powder, mixed with 
sand, presents no difficulty, as the active principles are all soluble in 
the official menstruum, but in order to insure complete exhaustion, 
the percolate should be collected in drops, very slowly. 

Tinctura Moschi. Musk will yield to water about 50 or 60 per 
cent, of its weight of soluble matter, whereas alcohol extracts only 
about 10 per cent. ; the official mode of manipulation can be advan- 
tageously modified by macerating the musk with the water, for twelve 



TINCTURES. 249 

hours, before adding the alcohol. The persistent odor of musk can 
be removed from mortars and graduates by means of quinine or 
powdered ergot, made into a soft paste with water and spread over 
the surface of the apparatus. 

Tinctura Nucis Vomicce. The present official formula is very simple 
and insures a tincture of uniform strength, containing 0.003 Gm. of 
mixed alkaloids in each Cc. 

Tinctura Opii. Although the Pharmacopoeia directs the use of 
powdered opium, for the sake of uniformity, a somewhat coarser state 
of division is preferable, and percolation to complete exhaustion can 
be carried on more satisfactorily with opium in No. 40 powder. The 
preliminary digestion with water, for twelve hours, prepares the 
soluble principles for better extraction with the diluted alcohol, and a 
somewhat coarser powder prevents compaction of the mass. The 
insoluble calcium phosphate is intended to facilitate the percolation 
of the fine powder, but does this very imperfectly. Official tincture 
of opium must contain from 0.013 to 0.015 Gm. of crystallized 
morphine in each Cc. 

Tinctura Opii Deodorata. The active virtues of opium can be com- 
pletely extracted with water ; the maceration for twelve hours should, 
however, be accompanied by frequent agitation, and subsequent per- 
colation continued until the liquid passes but slightly imbued with 
the peculiar taste of opium. The treatment of the concentrated per- 
colate with ether, as directed in the Pharmacopoeia, is intended to 
remove a peculiar odorous principle and narcotine, which it does very 
effectually, but if the official modus operandi be strictly followed — 
namely, to shake the ether repeatedly with the aqueous solution — a 
very annoying and persistent emulsion will generally result. A much 
better plan is to add the ether to the liquid in a cylinder or large 
globular separator aud bring the two fluids into intimate contact, 
either by slowly inverting the cylinder or by rotating the separator ; 
this treatment should be continued for some time, and repeated fre- 
quently during twelve or twenty-four hours. The aqueous fluid 
should then be carefully separated, either by being drawn off or by 
decanting or siphoning off the ether, and the washing with ether 
repeated, this time using about one-half as much ether as before. 

Experiments made with benzene aud petroleum benzin as deo- 
dorizing agents have proven their inferiority to ether, mainly on 
account of their own disagreeable and rather persistent odor. In my 
experience, the most satisfactory plan is to deodorize the powdered 
opium itself with ether, by treating it three times after the manner 
prescribed in the Pharmacopoeia for "Opium Deodoratum," and then 
to exhaust this thoroughly with water, concentrate the percolate to 
four-fifths of the intended volume of finished product, and add the 
necessary quantity *of alcohol ; this method involves the use of a 
larger quantity of ether (which can be redistilled aud used for a sub- 
sequent operation), but entirely obviates the formation of troublesome 
emulsions, and yields au unobjectionable product. 



250 PRACTICAL PHARMACY. 

Federer's process for deodorizing opium by freezing an aqueous 
infusion, which was published in full in the Druggists' Circular for 
April, 1887, is economical and not very troublesome; it removes all 
odor and narcotine, but I have also invariably noticed a loss of mor- 
phine when operating with assayed opium. The marc was carefully 
tested and found completely free from morphine, proving that the 
loss occurred in the dark deposit separated during the freezing 
operation. 

The morphine strength of this tincture is identical with that of the 
plain tincture of opium. 

Tindura Physostigmatis. Tincture of Calabar bean should be pre- 
served in small, well-stoppered vials, protected against light, on 
account of the sensitiveness of the alkaloidal salts, when in solution, 
to the influence of air and light. 

Tindura Qaassice. No tannin being contained in quassia, the tinc- 
ture is not discolored by iron salts, and is often selected from among 
the bitter stomachics on that account. 

Tindura Quillajai. Boiling water extracts all the saponaceous 
principles from quillaja, but also considerable inert matter, which is 
sought to be removed, in the official process for making the tincture, 
by addition of alcohol ; the latter also finally preserves the fiuished 
product. 

Tindura Sanguinarice. The addition of acetic acid to the men- 
struum not only facilitates the exhaustion of the drug, but also 
materially improves the stability of the tincture. 

Tindura Strophanthi. Strophanthus seeds contain considerable 
fixed oil, which can be removed by percolation with ether, before using 
the official menstruum; ether does not affect the active principle stro- 
phanthin, which is perfectly soluble in diluted alcohol. 



CHAPTER XXI. 

WINES AND VINEGAES. 

These two classes of preparations have almost passed into disuse 
among physicians, and their number has been diminished in the last 
Pharmacopoeia ; in place of thirteen wines officially recognized in 
1880, only ten now remain, and the number of vinegars has been 
reduced from four to two. 

"Wines. 

Both white and red wines are recognized in the Pharmacopoeia, but 
in the preparation of the official medicated wines, only the white wine 
is directed, on account of its lesser astringency, and in each case the 
alcoholic strength of the preparation is increased by the addition of 
alcohol to the extent of 15 per cent. This fortification of the wine 
is particularly necessary to insure the stability of vegetable solutions 
during warm weather. Native wines can now be obtained of good 
quality, and are given preference by the Pharmacopoeia. The chief 
difference between white and red wines lies in the dark coloring 
matter and larger proportion of tannin in the latter, due to the fact 
that, in the case of red wines, the pericarp, or skin of the grape, is 
allowed to remain with the expressed juice during fermentation ; were 
the skins carefully removed, many dark-colored grapes would also 
yield white wines, for the juice is naturally colorless. Much of the 
tannin found in wines may also be derived from the casks in which 
they are stored. As white wines, as a rule, contain only very small 
proportions of tannin, they are preferred as menstrua for medicated 
wines. 

The process of freeing wines from tannin is termed detannating 
them, and may be effected by adding to the wine either some freshly- 
prepared ferric hydroxide or some sweet milk ; the former plan is 
the most effectual, although the most laborious, but should not be 
employed if the wine is wanted entirely free from iron, some of 
which goes into solution. As the removal of tannin from wine in no 
way interferes with its quality — alcoholic strength and aroma re- 
maining the same, and only coloring matter being lost — a supply of 
detannated wine should be kept on hand, for it requires very little 
more labor to detannate a gallon than a pint. Wines containing 
tannin are not well suited for use with alkaloidal drugs, iron salts, 
antimony compounds, etc., as precipitates will be gradually formed 
and deposited. The detannating agent must be allowed to remain in 



252 PRACTICAL PHARMACY. 

contact with the wine for some days, with occasional agitation, until a 
few drops of tincture of ferric chloride, added to a small portion of the 
wine, no longer produce a dark color. 

If ferric hydroxide is to be used, it must be freshly prepared, and a 
convenient quantity then be added to the wine — about 8 ounces of 
the expressed, but moist, precipitate to a gallon. Sweet milk may 
be employed in the proportion of 4 fluidounces to a gallon. 

Both white and red wines have an acid reaction, due to potassium 
bitartrate held in solution ; this acidity is limited, by the Pharmaco- 
poeia, to from 4.49-7.78 Gm. of free acid per liter. The amount of 
solid matter in wines should range between 1.5 and 3.5 percent., and 
may be ascertained by evaporation and drying on the water- bath 
during twelve hours. The Pharmacopoeia also specifies the alcoholic 
strength to be from 10-14 per cent, by weight, which is equal to 
12.4-17.3 per cent, by volume of absolute alcohol, the official direc- 
tions for ascertaining the percentage of alcohol present being to take 
the specific gravity of the wine at 15.6° C. (60° F.), evaporate a 
carefully measured portion of it, in a tared capsule, to one-third of its 
weight, cool and restore the original volume by the addition of water, 
and again takethe specific gravity of the liquid at 15.6° C. (60° F.) ; 
the difference between the two specific gravities subtracted from 
1.000, indicates the specific gravity of an alcohol containing the same 
percentage of absolute alcohol as the wine, the corresponding percent- 
age being ascertained by reference to the alcoholometric tables pub- 
lished in the Pharmacopoeia. Suppose the wine before evaporation 
has a specific gravity of 0.9930, and after evaporation and addition 
of water, 1.0098, then 1.0098 — 0.9930=0.0168, and 1.000 
— 0.0168 = 0.9832 ; by referring to the tables it is found that alcohol 
of 0.9832 specific gravity at 15.6° C. (60° F.) contains between 10 and 
11 per cent, by weight, or between 12 and 13 per cent, by volume, of 
absolute alcohol. 

Red wines are frequently colored artificially with aniline, which 
coloration may be detected by the tests officially directed for that 
purpose. If red wine be mixed with twice its volume of potassa 
solution and a small quantity of chloroform, and the mixture then 
carefully heated, the presence of certain aniline colors will develop a 
very disagreeable odor, due to the formation of isonitril. Fuchsine 
may be detected by the crimson color imparted to uncolored silk fibre 
placed in contact with a mixture of acetic acid and an ethereal 
extract of red wine previously treated with ammonia water in excess ; 
as the mixture is evaporated in a porcelain dish, the color is de- 
veloped. Hydrochloric acid should not produce red color if added 
to a filtrate obtained from shaking warm red wine with manganese 
dioxide, showing the absence of sulpho-fuchsine. 

The Official Medicated Wines. Of these, two are prepared 
by percolation, two by maceration, and four by simple solution of 
the medicinal agent in the menstruum. 



WIXES AXB VIXEGAES. 



253 



Table of Official, Wines showing Strength and Menstruum Used. 
Made by Percolation. 



Official Name. 



Quantity of drug used 
for 1000 Cc. 



Yinum— 
Colcbici Radicis 

Ergotae . . . 



Colchicum 400 Gm 1 
Root j 

Ergot 150 Gm. 



Fineness of 
Powder. 



No. 30 
No 30 



Menstruum. 



Quantity of 
Menstruum 

tised for 
moistening 
the drug. 



White Wine 850 Cc. 1 , An n 

Alcohol 150 " f 10 ° Lc - 

White Wine 850 " 1 

Alcohol 150 " ( 



Cc 



Owing to the weak alcoholic menstruum, both drugs should be 
packed only moderately. 

Made by Maceration. 



Official Name. 



Quantity of drug used 
for 1000 Cc. 



Yinum — (Colchicum 150 Gm. 

Colchici Seminis . \ Seed 

I Opium 100 Gm. 

Opii < Cinnamon 10 ' ' 

I ( Cloves 10 " 



Fineness of 
Powder. 



Menstruum. 



No. 30 
Fine Powder 



/White Wine 850 Cc. ) 
j Alcohol 150 " ; 



Length of 

time of 
Maceration . 



7 days . 



No. 60 [White Wine 850 

No. 30 1 Alcohol 150 



7 days. 



Wine of opium is of the same morphine strength as the tincture, 
namely, 0.013-0.015 Gm. in each Cc. 

Made by Simple Solution. 



Official Name. 



Yinum Antimonii 



Yinum Ferri Amarum 



Yinum Ferri Citratis 



Yinum Ipecacuanha? 



Composition. 








\ Antimony and Potassium Tartrate 
J Boiling Distilled Water ... 




4Gm. 
65 Cc. 
150 " 


L White Wine, sufficient to make . 
f Soluble Iron and Quinine Citrate 
J Tincture of Sweet Orange Peel . 






1000 " 
50 Gm. 
150 Cc. 
300 " 


l_ White Wine, sufficient to make . 

| Iron and Ammonium Citrate 

J Tincture of Sweet Orange Peel . 




1000 " 
40 Gm. 
150 Cc. 
100 " 


[ White Wine, sufficient to make . 
f Fluid Extract of Ipecac 






1000 " 
100 " 
100 " 


( White Wine 






800 " 



Vinegars. 

The valuable solvent as well as preservative properties of diluted 
acetic acid, were at one time employed for a larger class of prepara- 
tions than at present, of which the v vinegar of opium and vinegar of 
squill alone are now recognized in the Pharmacopoeia. The official 
diluted acetic acid is made by mixing one part of 36 per cent, acetic 



254 PRACTICAL PHARMACY. 

acid with five parts of water, and contains, therefore, 6 per cent, of 
absolute acetic acid. 

The Official Vinegars. These are made by maceration and 
subsequent expression, and represent 10 Gm. of the drug in 100 Cc. 
of finished product. 

Acetum Opii. Vinegar of opium is made by macerating 100 Gm. 
of powdered opium and 30 Gm. of nutmeg in No. 30 powder, with 
500 Cc. of diluted acetic acid, for seven days, with frequent agitation ; 
after expressing the liquid, the residue is mixed with 200 Cc. of 
diluted acetic acid and again expressed. After mixing and filtering 
the liquids, 200 Gm. of sugar are dissolved in the filtrate, and suf- 
ficient diluted acetic acid is added to bring the volume up to 1000 Cc. 

Vinegar of opium is of the same morphine strength as the tincture 
and wine, containing 0.013 to 0.015 Gm. in each Cc. 

Acetum Scilke. Squill is readily exhausted by diluted acetic acid. 
The Pharmacopoeia directs the use of a No. 30 pow T der, but as the 
drug swells considerably from absorption of the menstruum, a No. 20 
powder will be preferable; 100 Gm. of squill are macerated with 
900 Cc. of diluted acetic acid, for seven clays, with occasional agita- 
tion, after which the mixture should be strained with expression, and 
the residue washed with sufficient diluted acetic acid to bring the 
volume of the strained liquid up to 1000 Cc. It will be found 
advantageous to set the strained liquid aside for three or four days 
before filtering it. 



CHAPTER XXII. 

FLUID EXTRACTS. 

The term fluid extract, in its present acceptation, is applied to 
concentrated alcoholic or hydro-alcoholic solutions of vegetable prin- 
ciples, which are permanent and represent all the active virtues of 
the drugs from which they are made ; they are officially recognized 
in the Pharmacopoeias of the United States, Great Britain, Ger- 
many, and Switzerland, differing but slightly in strength in the four 
countries. 

Fluid extracts, or liquid extracts, as they are called in Great 
Britain, were first introduced about the year 1832; their origin, 
although generally credited to American pharmacy, belongs more 
probably to England, since in 1834 English fluid extracts were 
already known in this country. Prior to 1847 very little interest 
appears to have been taken in this class of preparations in the 
United States, only three fluid extracts being on record as in use 
at that time — namely, senna, valerian, and rhubarb ; from that time 
forward, fluid extracts grew in favor, and the Pharmacopoeia of ] 850 
gave working formulas for seven concentrated solutions, of which, 
however, only one — valerian — is deserving of the title of fluid 
extract in the present definition of that term ; two were oleoresins, 
cubebs and black pepper, and four concentrated syrups, rhubarb, 
sarsaparilla, senna, and spigelia and senna. In 1860 the number of 
fluid extracts officially recognized was increased to ticenty-five, in 1870 
to forty-six, in 1880 to seventy-nine, and in the present (1890) edition 
of the Pharmacopoeia eighty-eight are directed. 

Prior to 1880 the strength of fluid extracts, as prescribed by the 
Pharmacopoeia, was 1 grain of drug to 1 minim of fluid extract; 
since that time the pharmacopoeial strength is based upon the relation 
of the metric measures of weight and capacity, so that any weight 
of a given drug is to be converted into a fluid extract having the 
bulk of the same weight of water at its maximum density, or, in 
other words, one gramme of the drug is represented by one cubic cen- 
timeter of the fluid extract. The present strength of official fluid 
extracts is about 5 per cent, weaker than formerly. British liquid 
extracts, with the exception of those of male fern, cinchona, opium, 
pareira, and liquorice, are of the strength of one avoirdupois ounce 
to one imperial fluidounce, which practically corresponds to our own. 
In Germany, each gramme of drug is represented by one gramme of 
fluid extract, the relation being weight for weight. 

All the official fluid extracts are directed to be prepared by perco- 



256 PRACTICAL PHARMACY. 

lation, a menstruum uniform in alcoholic strength being employed 
during the process of exhaustion. When, however, glycerin is used 
with the first portion of the menstruum, percolation is continued and 
finished with a liquid of the same alcoholic strength, but not mixed 
with glycerin ; the only exception to this is in the case of fluid ex- 
tract of wild cherry, where the drug is moistened and packed with 
a mixture of glycerin aud water, and then percolated with alcohol 
and water. With the exception of castanea and triticum, a certain 
portion of the stronger percolate is set aside as a reserve, and the 
weaker percolate is directed to be evaporated to a soft extract, which 
is dissolved in the reserved portion, the requisite volume of finished 
product being made up with fresh menstruum containing no gly- 
cerin. By evaporating the weak percolate to a soft extract, most of 
the water is also expelled, and the comparatively small portion 
remaining with the extract will occasion but a slight change in the 
menstruum of the reserved portion, which, at the same time, is the 
best solvent for the extractive matter ; finally, the addition of fresh 
menstruum will not chauge the alcoholic strength of the liquid. 

It is important that the exhaustion of the drug be conducted as 
carefully as possible, so that the reserved portion may represent a 
solution of nearly the whole active virtues of the drug ; with this end 
in view the rate of percolation for 1000 Gm. of drug should be 
adjusted to about 8 drops per miuute, at which rate about 20 Cc. can 
be collected in an hour. In the hands of a careful operator handling 
such quantities as are given in the pharmacopoeial formulas, the offi- 
cial process yields very satisfactory results, and the danger arising 
from evaporation of the weak percolate may well be disregarded, 
since from 90 to 95 per cent, of the active principles are most likely 
contained in the reserved portion, therefore, only a trifling proportion 
of the medicinal virtues of the drug will be subjected to heat. 

The official directions for the preparation of fluid extracts are 
intended for the quantity of drug designated in the formulas, and 
must of necessity often be modified by manufacturers who operate 
upon hundreds of pounds at one time; fineness of powder, degree of 
packing and rate of percolation must be adapted to the quantity of 
material in hand. Manufacturers, in some cases, resort to repeated 
maceration and expression instead of percolation. 

Special authority is given by the Pharmacopoeia to employ, where 
it may be applicable, the process of repercolation without change of 
initial menstruum. This process, which is fully described on page 
130, is followed by several manufacturers, and does away with the 
possibility of injury from application of heat. Repercolation is par- 
ticularly adapted to the preparation of fluid extracts, and the only 
objection that can be urged against its use is the enforced necessity of 
carrying on hand a series of bottles containing weak percolates, for 
each fluid extract made; disregarding this annoying feature, the pro- 
cess is less troublesome than auy other, and in the case of some drugs 
must yield fluid extracts of superior quality. 



FL UIJD EX TEA CTS. 257 

All fluid extracts, no matter how carefully made, will begin to 
deposit soon after they are completed, aud this precipitation will con- 
tinue for a varying length of time. The menstruum dissolves certain 
extractive principles which it is incapable of retaining in perfect 
solution afterward under all changes of temperature, and thus far no 
method is known to entirely prevent such separation, which is aug- 
mented by exposure to light, air, and heat. Fluid extracts prepared 
entirely without heat are less prone to deposit than when made by the 
official process, and in these the amount of precipitate is often found 
very trifling; happily frequent examinations of precipitates in fluid 
extracts have disclosed the fact that they consist chiefly of inert 
extractive matter, and therefore do not affect the medicinal value of 
the preparation. All freshly made fluid extracts should be set aside 
in well -stoppered glass vessels, in dark aud moderately cool places, for 
a period of two or three months, before filtering and bottling them; 
this plan is universally followed by large manufacturers, and ex- 
plains the absence, in many cases, of appreciable deposits. Pharma- 
cists will find that fluid extracts can be made from select drugs, on a 
small scale, as perfectly as in large quantities, and simple appear- 
ance, so often misleading, is no criterion as to quality. 

With the exception of the fluid extracts of castanea, nux vomica, 
triticum, and wild cherry, all the fluid extracts of the Pharmacopoeia 
are prepared by the following general formula ; the quantity of men- 
struum for moistening the drug, the degree of pressure to be used in 
packing, and the quantity of percolate to be set aside as reserve being 
specified in each case : 

1000 Gm. of the powdered drug of the prescribed degree of fine- 
ness are thoroughly moistened with a certain quantity of the initial 
menstruum and packed more or less firmly in a cylindrical percolator ; 
the drug having been properly covered with a paper diaphragm, enough 
menstruum is poured on to completely saturate the powder and leave a 
stratum above it. When the liquid begins to drop from the percolator, 
close the lower orifice, and having closely covered the percolator to pre- 
vent evaporation, macerate for forty-eight hours. Then allow percola- 
tion to proceed slowly, gradually adding menstruum (alcohol or alcohol 
and water), until the drug is exhausted. Reserve the first 700 to 900 
Cc, of the percolate, and evaporate the remainder, at a temperature not 
exceeding 50° O. (122° F.), to a soft extract; dissolve this in the re- 
served portion and add enough menstruum to make the fluid extract 
measure 1000 Cc. 

The concentration of the weak percolate is usually effected by dis- 
tilling off the alcohol, in a suitable apparatus on a water-bath, and 
finally evaporating the liquid, in a porcelain capsule, to the proper 
consistence, preferably with constant stirring. The Pharmacopoeia 
does not in every case specify the temperature for evaporation, but 
it is best to keep it always below 50° C. (122° F.), so as to avoid 
changes in the extractive, as far as possible. 

Of the eighty-eight official fluid extracts, seventeen are made with 

17 



258 PRACTICAL PHARMACY. 

alcohol alone, two with alcohol aod glycerin, twenty-one with diluted 
alcohol, forty-six with various mixtures of alcohol and water, or 
alcohol, water, and glycerin, and in two, water only is used as a men- 
struum, although the preparation is finally preserved with alcohol ; 
altogether, sixteen contain glycerin. In the case of four drugs, 
conium, ergot, nux vomica, and sanguinaria, acetic acid is added to 
the initial menstruum, to facilitate the extraction of the alkaloidal 
principles present; in the case of senega and of glycyrrhiza, am- 
monia water is added to the solvent, to prevent gelatinization in the 
former fluid extract, and to insure complete solution of the sweet 
principle in the latter drug. Arranged according to the menstruum, 
the official fluid extracts may be divided into twenty-one classes, as 
follows : 

Made with alcohol : Aromatic powder, buchu, calamus, cannabis 
indica, capsicum, cimicifuga, cubeb, gelsemium, ginger, grindelia, 
iris, kusso, lupulin, mezereum, savin, veratrum viride, xanthoxylum. 

Made with alcohol 4 volumes, glycerin 1 volume : Cinchona. 

Made with alcohol 3 volumes, glycerin 1 volume : Cotton-root 
bark. 

Made with alcohol 4 volumes, water 1 volume : Belladonna root, 
eriodictyon, podophyllum, rhubarb, serpentaria. 

Made with alcohol 3 volumes, water 1 volume : Aconite, arnica 
root, black-haw, calumba, eucalyptus, guarana, ipecac, leptandra, 
matico, squill, stramonium seed, valerian, viburnum opulus. Same 
menstruum with addition of acetic acid : Nux vomica, sanguinaria. 

Made with alcohol 2 volumes, water 1 volume : Bitter orange 
peel, chirata, colchicum root, colchicum seed, digitalis, hyoscyamus, 
menispermum, phytolacca root. 

Made with diluted alcohol : Asclepias, chimaphila, coca, conval- 
laria, cypripedium, dulcamara, eupatorium, gentian, lappa, lobelia, 
pilocarpus, rhamnus purshiana, rumex, scoparius, Scutellaria, senna, 
spigelia, stillingia, taraxacum. Same menstruum with addition of 
acetic acid : Conium, ergot. 

Made with alcohol 5 volumes, water 8 volumes: Frangula. 

Made with alcohol 1 volume, water 2 volumes : Quassia, sarsa- 
parilla. 

Made with alcohol 72 volumes, Avater 18 volumes, glycerin 10 
volumes: Pareira. 

Made with alcohol 65 volumes, water 25 volumes, glycerin 10 
volumes : Apocynum. 

Made with alcohol 6 volumes, water 3 volumes, glycerin 1 volume : 
Aspidosperma, hydrastis, rubus. 

Made with diluted alcohol 9 volumes, glycerin 1 volume : Gera- 
nium, krameria, rhus glabra, red rose. 

Made with alcohol 5 volumes, water 8 volumes, glycerin, 1 volume : 
Hamamelis. 

Made with alcohol 3 volumes, water 6 volumes, glycerin 1 volume : 
Sarsaparilla (compound fluid extract). 



FLUID EXTRACTS. 



259 



Made with alcohol 2 volumes, water 5 volumes, glycerin 3 vol- 
umes : Uva ursi. 

Made with alcohol 75 volumes, water 20 volumes, ammonia water 
5 volumes: Senega. 

Made with alcohol 30 volumes, water 65 volumes, ammonia water 
5 volumes: Glycyrrhiza. 

Made with water 2 volumes, glycerin 1 volume, followed by a 
mixture of alcohol So volumes, water ]5 volumes : Wild cherry. 

Made with boiling water : Triticum. The finished product con- 
tains about 25 per cent, by volume of alcohol. 

Made with boiling water and cold water: Castanea. The finished 
product contains 10 per cent, by volume of glycerin and about 20 
per cent, by volume of alcohol. 



Alphabetical List of Official Fluid Extracts, 

Showing the fineness of powder, menstruum, degree of moisture, and reserve percolate 
directed by the Pharmacopoeia. 



Name. 



Fluid Extract of- 
Acouite 



Apocynum . 



Arnica Root 

Aromatic Powder 
Asclepias . 



Aspidosperma . 

Belladonna Root 
Bitter Orange Peel 



Buchu 

Calamus 

Calumba . 

Cannabis Indica 
Capsicum . 

Castanea . 

Chimapbila 

Chirata 

Cimicifuga 

Cinchona . 

Coca . 

Colcbicum Root 

Colchicum Seed 



Conium 

Convallaria 

Cotton Root Bark 

Cubeb . . 
Cypripedium . . 

Digitalis 

Dulcamara . 




No. 60 



60 



No. 60 
" 60 

" 60 

" 40 

" 60 
" 60 



Initial Menstruum. 




/ Alcohol 
\ Water 
( Alcohol 
1 Glycerin 
(Water 
l (Alcohol 
| Water 

Alcohol 

Diluted Alcohol 
(Alcohol 600 Cc. 

■{ Glycerin 100 " 

(Water 300 " 

] f Alcohol 800 " ") 

\ Water 200 " j" 

| Alcohol 600 " > 

\ Water 300 " J 

Alcohol 

Alcohol 
( Alcohol 750 Cc. \ 

X Water 250 " j 

Alcohol 

Alcohol 
J Boiling Water followed ") 
I by Cold Water j 

Diluted Alcohol 
/Alcohol 600 Cc.) 

(Water 300 " / 

Alcohol 
< Alcohol 800 Cc. "> 

I Glycerin 200 " j 

Diluted Alcohol 
/Alcohol 600 Cc") 

j Water 300 " / 

/Alcohol 600 " I 

X Water 300 " j" 

(Diluted Alcohol 980 " 1 
{Acetic Acid 200 " j 

Diluted Alcohol 
/Alcohol 750 Cc.) 

(Glycerin 250 " j 

Alcohol 

Diluted Alcohol 
/Alcohol 600 Cc. "I 
\ Water 300 «' j 

Diluted Alcohol 



Quantity of 
Menstruum 
to moisten 
1000 Gin. of 

the drug. 



400 Cc. 
400 " 

400 " 

350 " 
400 " 

400 " 



400 
350 

300 

300 
500 



400 
350 
250 
350 
450 
350 

300 

300 

400 

500 

400 
400 

400 

400 



Reserve. 



900 Cc. 
900 " 

900 " 

850 " 
900 " 

800 " 



800 

850 
900 

700 

900 

900 



700 
850 
900 
750 
800 
850 

850 

900 

800 

700 

900 
900 

850 

800 



260 



PRACTICAL PHARMACY. 





| 




Quantity of 






Fineness , 




Menstruum 




Name. 


of 
powder. 

! 


Initial Menstruum. 


to moisten 

1000 Gm. of 

the drug. 


Reserve. 


Fluid Extract of— 










Ergot 


No. 60 


/ Diluted Alcohol 980 Cc. ' 
i Acetic Acid 20 " 


300 Cc. 


850 Cc 


Eriodictyon .... 


" 60 


/Alcohol 800 " 1 
(Water 200 " 


400 « 


900 " 


Eucalyptus .... 


" 40 


K Alcohol 750 " 1 
\ Water 250 " 


400 " 


900 " 


Eupatorium .... 


" 40 


Diluted Alcohol 


400 " 


800 " 


Frangula 


" 40 ; 


f Alcohol 500 Cc. 1 
(Water 800 l< J 


350 " 


800 " 


Gelsemium .... 


" 60 


Alcohol 


300 " 


900 " 


Gentian 


" 30 


Diluted Alcohol 


350 " 


800 " 


Geranium ... 


" 30 


(Diluted Alcohol 900 Cc] 
(Glycerin 100 " J 


350 " 


700 " 


Ginger 


" 40 


Alcohol 
f Alcohol 300 Cc' 


250 " 


900 " 


Glycyrrhiza .... 


" 40 


-< Ammonia Water 50 " 
(Water 650 " 


> 350 " 


750 " 


Grindelia 


" 30 


Alcohol 


300 " 


850 " 


Guarana 


" 80 


f Alcohol 750 Cc." 
1 Water 250 " 
( Alcohol 500 " ' 


200 " 


800 " 


Hamamelis .... 


" 40 


■{ Glycerin 100 " 
( Water 800 " 


350 " 


850 " 














(Alcohol 600 " * 






Hydrastis 


" 60 


-{ Glycerin 100 '* 
(Water 300 " , 


300 " 


850 " 


Hyoscyamus .... 


" 60 


(Alcohol 600 " 
1 Water 300 " 


400 " 


900 " 


Ipecac 


" 80 


/Alcohol 750 " 
'(Water 250 " 


I 350 " 


900 " 


Iris 


" 60 


Alcohol 


400 " 


900 " 


Kousso 


" 40 


Alcohol 


400 " 


900 " 


Krameria 


" 30 


/Diluted Alcohol 900 Cc. 
(Glycerin 100 " 


► 400 " 


700 " 


Lappa 


" 60 


Diluted Alcohol 


400 « 


S00 " 


Leptandra 


" 60 


J Alcohol 750 Cc. 
\ Water 250 " 


L 400 " 


800 " 


Lobelia . 


" 60 


Diluted Alcohol 


350 ■« 


850 " 


Lupulin 




Alcohol 


200 " 


700 " 


Matico 


" 40 


( Alcohol 750 Cc. 
"(Water 250 " 


I 300 " 


850 " 


Menispermum .... 


" 60 


/Alcohol 600 '* 
(Water 300 " 


| 400 " 


900 " 


Mezereum 


" 30 


Alcohol 
f Alcohol 750 Cc" 


400 " 
) 


900 " 


Nux vomica .... 


" 60 


\ Water 250 " 
(Acetic Acid 50 " 
(Alcohol 720 " " 


>. 1050 " 

1 




Pareira 


" 40 


\ Glycerin 100 " 
/ Water 180 " 


>■ 400 " 


850 " 


Phytolacca Boot 


" 60 


/Alcohol 600 " 
(Water 300 " 


I 400 " 


800 " 


Pilocarpus 


" 40 


Diluted Alcohol 


350 " 


850 " 


Podophyllum .... 


" 60 


/ Alcohol 800 Cc. 
(Water 200 " 


[■ 300 " 


850 " 


Quassia 


" 60 


/Alcohol 300 " 
(Water . 600 " 


| 400 " 


900 " 


Rhamnus Purshiana . 


" 60 


Diluted Alcohol 


400 " 


'800 " 


Rhubarb 


" 30 


/Alcohol 800 Cc. 
(Water 200 " 


I 400 " 


750 " 


Rhus Glabra .... 


'• 40 


/Diluted Alcohol 900 " 
(Glycerin 100 " 


1 350 il 


800 " 


Rose 


" 30 


/Diluted Alcohol 900 " 
(Glycerin 100 " 
(Alcohol 600 " 


1 400 » 
) 


750 " 


Rubus 


" 60 


\ Glycerin 100 " 


V 350 " 


700 " 






(Water 300 " 




Rumex 


" 40 


Diluted Alcohol 
f Alcohol 225 Cc. 


350 " 
) 


800 " 


Sanguinaria 


" 60 


< Water 75 " 
(.Acetic Acid 50 " 


V 350 " 


850 " 


Sarsaparilla .... 


" 30 


/Alcohol 300 " 
(Water 600 " 


| 400 •« 


800 " 



FLUID EXTRACTS. 



261 



Name. 



Fluid Extract of— 

Sarsaparilla, Compound 



Savin . 
Scoparius . 
Scutellaria. 



Senega 

Senna 

Serpentaria 

Spigelia 

Squill 

Stillingia . 

Stramonium Seed 

Taraxacum 
Triticum . 



Uva Ursi . 

Valerian . 
Veratrum Viride 
Viburnum Opulus 

Viburnum Prunifolium 

Wild Cherry 
Xantboxylum . 



Fineness 

of 
powder. 



" 40 

" GO 

" 40 

" 40 

" 30 

" 60 

" 60 

" 20 

" 40 

" 60 

" 30 
Finely cut 

No. 30 

" 60 

" 60 



Initial Menstruum. 



( Alcohol 300 

•I Glycerin 100 

( Water 600 

Alcobol 

Diluted Alcohol 

Diluted Alcohol 
[ Alcobol 750 

■< Ammonia Water 50 
(.Water 200 

Diluted Alcohol 
[ Alcohol 800 

\ Water 200 

Diluted Alcohol 
$ Alcohol 750 

\ Water 250 

Diluted Alcohol 
( Alcohol 750 

\ Water 250 

Diluted Alcohol 

Boiling Water 



[Alcobol 
< Glycerin 
(Water 
(Alcohol 
\ Water 

Alcohol 
[Alcohol 
\ Water 

{Alcohol 
Water 
[Glycerin 
I Water 



200 
300 
500 
750 
250 

750 
250 
750 
250 
100 
200 



<j followed by a mixt 
| Alcohol 850 

L Water 150 

Alcohol 



Quantity of 
Menstruum 
to moisten 
1000 Gm. of 
the drug. 



400 Cc. 

250 " 

350 " 

350 " 

450 " 

400 " 

300 " 

200 " 

300 " 

300 " 

200 " 

300 " 

400 " 



300 Cc. 
300 " 
300 " 

300 " 



250 



Reserve. 



000 
850 
800 

850 

800 
900 
750 
850 
850 
900 
850 



850 
900 
850 



900 



Special Remarks. 

Extr actum Casianece Fhddum. The exhaustion of chestnut leaves, 
by percolation with cold water, is a tedious operation and necessi- 
tates subsequent prolonged evaporation. If the leaves be strongly 
expressed after maceration with hot water, and this treatment be 
repeated once or twice, with half the quantity of fluid, the extraction 
of the active virtues of the drug will be complete. The addition of 
a considerable quantity of alcohol to the concentrated infusion causes 
the precipitation of mucilaginous and albuminous matter, which is 
removed, and the filtered liquid, after evaporation to a definite volume, 
is preserved by the addition of glycerin and a further quantity of 
alcohol. 

Extr actum Glycyrrhizw Fluidum. Liquorice root contains a sweet 
principle, glycyrrhizin, both in the free state and combined with 
ammonia, the former being insoluble but the latter soluble in cold 
water; the addition of ammonia-water to the menstruum is for the 
purpose of uniting ammonia with the free glycyrrhizin, and thus in- 
suring the solution of the total sweet principle present. If liquorice 



262 PRACTICAL PHARMACY. 

root which has been deprived of the brown corky layer be used, the 
flavor of the fluid extract will be far more agreeable. 

Extractum Lupulini Fluidum. Lupulin is very rich in resin, Avhich 
it yields readily to alcohol, and if the drug be moistened with one-fifth 
of its weight of menstruum, and then firmly packed as directed in 
the Pharmacopoeia, the mass will become almost impermeable to the 
menstruum subsequently added ; it is therefore better to pack the 
lupulin without previous moistening, which insures more satisfactory 
percolation. 

Extractum Nucis Vomicce Fluidum. There appears to be little 
necessity for this preparation alongside of the powdered extract and 
the tincture. The official directions, to digest the finely powdered drug 
for forty-eight hours, in a tightly-stoppered vessel, with a mixture of 
alcohol, water, and acetic acid, are important, and without this pre- 
liminary treatmeut complete exhaustion is very difficult, as the active 
principles are tenaciously imbedded in the homy albumiuous matter 
of the seed, which latter is softened by the acetic acid and heat. 
The entire percolate is reduced to a definite weight, and after de- 
termining the amount of alkaloids present, the residue is dissolved 
in alcohol and so much of a mixture of alcohol and water added 
that each Cc. of the finished product shall contain 0.015 Gm. of 
alkaloids, which makes the fluid extract five times as strong as the 
tincture of nux vomica. The volume of fluid extract obtainable 
from a soft extract of known alkaloidal strength can be easily calcu- 
lated ; thus, if the extract contains exactly 1.5 per cent, of alkaloid, 
each gramme of extract, containing 0.015 Gm. of alkaloid, will yield 
1 cubic centimeter of fluid extract; but if it contains more than 1.5 
per cent., theu each gramme will yield as many cubic centimeters as 
1.5 is contained times in the number expressing the percentage. For 
instance, should the extract contain 12.5 per cent, of alkaloids, each 
gramme will yield 8.33-1- Cc. of fluid extract; for 12.5-5-1.5=8.33 + . 
Proof: 1 Gm. at 12.5 per cent. = 0.125 Gm., and 0.125 Gm. -r- 
8.33+ = 0.015 Gm., the amount of alkaloid required by the Phar- 
macopoeia, in each Cc. 

Extractum Rhamni Purshiayice Fluidum. The official formula 
yields an efficient but intensely bitter preparation. Bark which has 
been stored at least two years should be used, so as to overcome the 
tendency to griping and other unpleasant effects. The so-called taste- 
less fluid extract of cascara is usually prepared with the aid of cal- 
cined magnesia, of which from 100 to 125 Gm. are mixed with 
1000 Gm. of the powdered bark and made into a soft paste with 
water ; after standing for twelve hours this is dried, again powdered, 
and percolated with diluted alcohol, as in the official extract. 

Extractum Pruni Virginians Fluidum. The formula for this fluid 
extract has been repeatedly changed with the view of insuring greater 
stability. A No. 30 powder of the bark seems better adapted for 
firm packing than No. 20, and the Pharmacopoeia orders an unneces- 
sarily strong alcoholic menstruum, the finished product containing 



FLUID EXTRACTS. 263 

60 per cent, of alcohol. A menstruum composed of alcohol 2 vol- 
umes, glycerin 2 volumes, and water 6 volumes, has been found to 
yield a very' satisfactory preparation, which precipitates but slightly, 
mixes clear with syrup, and retains the odor of hydrocyanic acid for 
a long time. Repercolation is best adapted for this fluid extract, 
since its value depends chiefly upon the volatile hydrocyanic acid, 
which is generated during the maceration and percolation of the 
drug. 

Extradural JRhei Fluidum. The very large proportion of alcohol 
directed in the official formula has been found necessary after a series 
of experiments with various mixtures of alcohol and water, both 
with and without the addition of glycerin. The present fluid extract 
precipitates only very slightly, and retains its original fluidity for 
several years, but does not form clear mixtures with aqueous or sac- 
charine liquids unless an alkali be added. 

Extractum Sanguinarice Fluidum. This fluid extract formerly caused 
much annoyance by copious precipitation on the bottom and sides of 
the containers. The presence of 5 per cent, of acetic acid and a less 
alcoholic menstruum -have been found to improve the character of the 
preparation, but precipitation can probably never be entirely pre- 
vented. 

Extractum Sarsaparillce Fluidum. Since glycerin has been dropped 
from the official menstruum, a slight increase in the alcoholic strength 
appears desirable, and although water alone is capable of extracting 
the virtues of sarsaparilla, a mixture of 2 volumes of alcohol and 
3 volumes of water will yield a better and more stable preparation. 

Extractum Scillaz Fluidum. A strongly alcoholic menstruum is 
desirable for squill, as the drug contains much gummy and albu- 
minous matter, which would affect the stability of the fluid extract. 

Extractum Scutellarice Fluidum. When made with diluted alcohol 
this fluid extract does not keep so well as when made with 2 volumes 
of alcohol and 1 volume of water ; hence the latter mixture is to be 
preferred. 

Extractum Senegal Fluidum. Ammonia water is used in the men- 
struum, to form soluble compounds with the pectin principles present 
in the drug, and thus prevent gelatinization of the fluid extract. 
The active virtues of senega are far more soluble in water than in 
alcohol, but the former also extracts larger proportions of pectin 
compounds, and these must be avoided as far as possible. A men- 
struum composed of 2 volumes of alcohol and 1 volume of water, 
with the addition of 5 per cent, of ammonia water, exhausts the drug 
thoroughly and yields a permanent preparation, hence the stronger 
alcoholic menstruum ordered by the Pharmacopoeia is unnecssary. 

Extractum Stillingke Fluidum. This fluid extract will sometimes 
gelatinize on standing; this may be avoided either by using a 
stronger alcoholic menstruum (alcohol 3 volumes, water 1 volume), 
or, what is still better, by adding sugar in the proportion of 10 or 12 
per cent, of the weight of the drug. 



264 PRACTICAL PHARMACY. 

Extractum Tritici Fluidum. Although the Pharmacopoeia directs 
percolation with boiling water to exhaustion, digestion of the finely- 
cut drug will be found preferable in every way, the operation to be 
repeated ouce or twice as maybe uecessary ; the infusion should then 
be rapidly concentrated, and when cold mixed with alcohol and set 
aside for two days, whereby the mucilaginous and albuminous matter 
is separated. The finished product contains 25 per cent, of alcohol, 
which protects the saccharine liquid against fermentation. 

Extractum Uvce Ursi Fluidum. The large quantity of glycerin, 30 
per cent , contained in the official fluid extract, is probably necessary 
in connection with the very weak alcoholic menstruum ordered, but 
a preparation keeping equally well can be made by using diluted 
alcohol and omitting the glycerin entirely. 

Extractum Veratri Viridis Fluidum. There seems to be little or no 
necessity for this preparation, as the drug is well represented by the 
tincture. If carefully made, the fluid extract is two and a half times 
as strong as the tincture, and presents all the alkaloids and resins of 
the drug, in the form of a concentrated solution. 



CHAPTER XXIII. 

EXTRACTS. 

Extracts are permanent, soft, solid, or dry preparations, obtained 
by evaporation of a solution of the medicinal principles of drugs. 
These solutions are prepared, as a rule, in the manner already ex- 
plained under fluid extracts, the solvents or menstrua employed 
being either water, water and alcohol, alcohol, or ether, according to 
the different menstrua used in their manufacture. Extracts are 
divided into aqueous, hydro-alcoholic, alcoholic, and ethereal, the last- 
named class being recognized in the Pharmacopoeia under the name of 
oleoresins. In fresh plants, the solution of the medicinal principles 
is represented by the juice, and may be obtained by expression ; 
extracts prepared by simple evaporation of the fresh juice of a plant 
are usually known as inspissated juices. 

Our Pharmacopoeia recognizes but one extract made from the 
fresh plant, extract of taraxacum, since the narcotic herbs which are 
extensively used in Europe for this purpose are not indigenous to this 
country. The juice is obtained from the fresh plant, after removal 
of extraneous matter, by bruising in a stone mortar with the aid of 
a hard- wood pestle until reduced to a smooth pulpy mass, which is 
then strongly expressed in canvas bags ; in order to recover all the 
juice, the residue is often mixed with water and again expressed. 
When the plant is not sufficiently moist to enable the formation of a 
soft pulp, water is sprinkled over it from time to time, as directed in 
the Pharmacopoeia. 

Besides the medicinal principles, the expressed juices of fresh herbs 
contain also mucilaginous and albuminous matter in solution and 
variable quantities of chlorophyll or green coloring matter in sus- 
pension ; of these the albuminous principles are most objectionable, 
as upon concentration of the juice they undergo change and are apt 
to render the finished extract tough and insoluble. Wheu roots are 
expressed, as in the case of the conn of colchicum, starch, which is 
present in the juice in place of chlorophyll, passes through the press- 
cloth, and must be removed by subsidence and decantation. The 
British, German, and French Pharmacopoeias direct the removal of 
albuminous matter by heating the juice to from 80° to 90° C. (176° 
to 194° F.) and filtering. The coagulated albumen envelops the 
green coloring matter and removes it also, which fact is disregarded 
in Germany and France, and accounts for the brown color of the 
extracts made from fresh herbs in those countries. In Great Britain 
the chlorophyll is carefully separated by heating the fresh juice to 



266 PRACTICAL PHARMACY. 

55° C. (131° F.) and straining through calico; the liquid is then 
heated to 93.3° C. (200° F.) and after filtering out the coagulated 
albumen, evaporated to a thin syrup, the chlorophyll is reincor- 
porated and evaporation continued, with constant stirring, to the 
proper consistence. This explains the firm condition and fine green 
color of the British narcotic extracts. The German Pharmacopoeia 
alone provides for the removal of the gummy matter, and hence its 
narcotic extracts are relatively much stronger than those of England 
and France. The solubility of gummy matter is not in any way 
affected by heating, and, therefore, the filtered liquid, after removal 
of the coagulated albumen and chlorophyll, is evaporated to 10 per 
cent, of the original weight of the fresh herb used, mixed with an 
equal volume of alcohol and set aside for twenty-four hours to allow 
the precipitated gum to subside. After decantation the precipitate is 
washed with diluted alcohol, which is added to the other clear liquid, 
and the whole evaporated to the condition of a soft solid. 

Considerable quantities of British extracts are annually imported 
into this country, and preferred by many pharmacists on account 
of their pilular consistence. In the case of the narcotic extracts, the 
superiority of the solid extracts made from the fresh juice of the 
herb is questionable, owing to the variability in the amount of ex- 
tract obtained from fresh plants ; besides, it must not be over- 
looked that the same name in the United States aud British Phar- 
macopoeias does not always indicate the same preparation, as, for 
instance, Extractum Aconiti, Extractum Belladonnce Alcoholicum, and 
Extraction Conii. 

Consistence of Extracts. The Pharmacopoeia recognizes 
two kinds of solid extracts, those of pilular consistence and those 
evaporated to complete dryness. A pilular consistence is such a 
condition as will allow the extract to be rolled into masses of 
pilular form without adhering to the fingers or subsequently losing 
shape ; this is rarely met with in the market, except in the case of 
British narcotic extracts, which derive their firmness chiefly from 
the chlorophyll and gummy matter present. Pilular consistence for 
the extracts made in this country, by the official formulas, is prac- 
tically unattainable at all seasons, for extracts made in summer are 
apt to become too hard in winter, whilst those evaporated to the proper 
consistence in winter are apt to soften in summer. Some extracts 
are apt to become tough and hard in the course of time, such as 
cinchona, quassia, and rhubarb; these are best retained in proper 
condition by incorporating with them, while still warm, 10 per cent, 
of their weight of glycerin, as suggested in the Pharmacopoeia. The 
condition of complete dryness is not applicable to all extracts, but 
can be readily maintained for all those so directed by the Pharma- 
copoeia, provided heat aud moisture be excluded. 

Changes by Evaporation. All plants contain one or more 
principles, which, though originally colorless, are very easily altered 
under the influence of air and heat, acquiring a yellow or brown color. 



EXTRACTS. 267 

It is not known whether the so-called colorless extractive is alike in all 
plants, neither is its composition or the nature of the changes produced 
under the conditions mentioned known, except that the heat of boil- 
ing water and the prolonged action of oxygen will convert it ulti- 
mately into a blackish insoluble substance, to which the name 
apotheme has been given, and which appears to be allied to humin. 
Extractive is almost insoluble in absolute alcohol and ether, but dis- 
solves freely in weaker alcohol and water, and is removed from its 
solution by animal charcoal and aluminum hydroxide, the more 
readily after it has become colored by oxidation. It is with difficulty 
freed from all admixtures, and the terms sweet, bitter, acrid, etc., as 
applied to extractives, refer to the same body in a more or less altered 
condition, combined or intimately mixed with other principles to which 
the peculiar taste is due. The injurious influence of air and heat upon 
the vegetable juices is mainly confined to the alterations of this 
extractive, and extends, in a limited degree only, to the majority of 
the well-defined principles. Its effects have often been much over- 
rated, except as regards the appearance of the extracts. The color 
of the different extracts varies with the nature of the drug from 
which they have been made, but should never be black. The char- 
acteristic taste, and to some extent also the odor of the drug, should 
be perceived in the extracts, and these should yield a nearly clear or 
moderately turbid solution with the menstruum used in their pre- 
paration. 

Aqueous Extracts. While decoction in some cases increases the 
yield of extract, by bringing into solution starch and other inert 
matter, it more frequently injures the quality of the product, by in- 
ducing changes in certain principles, which do not occur by infusion 
at lower temperatures. There is but one instance, that of extract of 
logwood, in which the Pharmacopoeia directs extraction by boiling, 
and this is on account of the difficulty of exhausting the tough 
wood. In Europe, digestion is still preferred for a few aqueous 
extracts, but, as a rule, maceration and percolation with cold water 
have been found to yield superior extracts. For the better extrac- 
tion of the active virtues of the drug, an addition of acid or alkali 
is sometimes made, as in the case of the official extracts of colchicum 
root and pure extract of glycyrrhiza. In the preparation of aqueous 
extracts the solution is freed from objectionable matter, whenever 
necessary, by heating to the boiling-point and straining before final 
evaporation. 

In 1889, the plan of concentrating large volumes of aqueous solu- 
tions of extracts by means of cold was formulated by M. Adrian, a 
French pharmacist, and put into practice on a large scale. Follow- 
ing up the suggestions of Herrera (1877), M. Adrian subjects the 
filtered aqueous solutions to a temperature of — 20° C. ( — 4° F.), in an 
ammonia-ice apparatus, and thus obtains large blocks of ice, in which 
the extractive solution is enveloped, the pure water alone freezing ; 
these blocks of ice are rapidly converted into snow, by means of 



268 PRACTICAL PHARMACY. 

large shaving machines. Another French pharmacist, M. Vee, pre- 
fers to convert the aqueous solution into a crystalline magma instead 
of solid blocks of ice, and accomplishes this by keeping the liquid 
in constant agitation during the freezing process. The snow-like 
mass is placed in centrifugal extractors, where about 75 per cent, of 
water is removed. The remaining solution is again subjected to 
cold (even a lower temperature than at first), when a syrupy liquid 
is obtained, which can readily be evaporated to a solid extract, in a 
vacuum apparatus, at a temperature not exceeding 30° C. (86° F.). 
Extracts thus prepared are lighter in color than those obtained by 
ordinary vacuum or open-air evaporation, form almost clear solutions 
with water, aud possess the odor and taste of the drug in a marked 
degree. It has been found that all vegetable matter in solution is 
retained in its original condition, even the albumen, water alone 
being removed. 

Alcoholic and Hydro- Alcoholic Extracts. For these two 
classes of extracts, percolation is decidedly the best method of extract- 
ing the medicinal principles of the drugs, the operation being con- 
tinued to complete exhaustion. In all cases but two — cinchona and 
hyoscyamus — of the official extracts directed to be made with alcohol 
or alcohol and water, the same menstruum is used throughout the 
process of percolation. In the two exceptions mentioned, a stronger 
alcoholic menstruum, equal to about three times the weight of the 
drug, is first employed, to be followed by a weaker alcoholic liquid ; 
exactly why this modification of the general plan has been ordered 
by the Pharmacopoeia for cinchona and hyoscyamus is not apparent. 
If percolation be slowly conducted, at the rate of about five drops per 
minute, from 3 to 4 cubic centimeters of percolate should suffice for 
each gramme of drug. In many cases, particularly those of the 
mydriatic drugs, whose active principles are easily split up by pro- 
longed application of heat, it is very desirable to set aside the first 
third of the percolate as reserve, to be incorporated with the remainder 
when this has been reduced to the condition of a syrupy fluid. The 
recovery of the alcohol is effected, as in the case of fluid extracts, by 
distillation in a suitable still, the final evaporation being conducted 
in porcelain dishes, with assiduous stirring, so as to insure a homo- 
genous mass and prevent the separation of resinous and other mat- 
ter. As the concentration of the solution approaches the condition 
of a thick syrup, continuous stirring is also necessary, to prevent the 
formation of a film, which, becoming gradually thicker, retards the 
evaporation of moisture, and consequently causes an accumulation of 
heat within the mass to the possible injury of some of the constitu- 
ents. In large manufacturing establishments mechanical stirrers are 
conveniently operated by steam, electric, or water motors. Metallic 
stirrers should never be employed, only those of porcelain, glass, or 
wood being admissible. To guard against the separation of coloring 
matter or changes in other constituents of the solution, concentration 



EXTRACTS. 269 

should always be effected on a water-bath, at a temperature not 
exceeding 55° C. (131° F.). 

There appears to be no reason why several of the official extracts 
should not be made by simple evaporation of the respective fluid ex- 
tracts, as already directed in the Pharmacopoeia for extract of ergot; 
the extracts of aconite, conium, digitalis, hyoscyamus, aud leptandra 
seem suitable for this method, as the menstrua used in the fluid extracts 
are identical with those directed for the extracts, and from 85 to 90 
per cent, of the fluid has not been subjected to heat at all. 

Of late years, powdered extracts have come exteusively into demaud. 
While their couvenieuce in dispensing pharmacy cannot be denied, it 
is questionable whether damage is not done in some cases by pro- 
longed exposure to the high temperature necessary to bring the pilu- 
lar extract to the proper condition for powdering, even with the 
addition of diluents. Of the seven dry extracts of the Pharma- 
copoeia, four are directed to be reduced to powder and the remaining 
three could also readily be brought to that condition ; as diluents, sugar 
of milk, powdered liquorice root, and rice flour may be used. In 
Germany, powdered narcotic extracts are prepared of one-half the 
original strength of the extract, by addition of finely powdered 
liquorice root, but in this country, manufacturers aim to furnish the 
powdered extracts of the original strength of the pilular extract, 
hence there is greater difficulty in preserving the pulverulent con- 
dition ; in the case of some extracts it is utterly impossible to convert 
them into powdered extracts weight for weight. Whenever possible, 
evaporation in a vacuum apparatus should be resorted to, so that the 
moisture may be rapidly driven off, at a low temperature. Messrs. 
Squire and Conroy, of England, have suggested calcined magnesia 
as the most desirable absorbent to use in making powdered extracts ; 
about 10 per cent, of the weight of a pilular extract should be used, 
the magnesia to be well mixed with the soft extract before evapora- 
tion to dryness. 

Very closely allied to extracts are two preparations which, although 
not partaking of the character of concentrated solutions, yet resemble 
some of the finished extracts in their physical properties ; they are 
purified aloes and purified ox-gall. 

Aloe Purificata, U. S. P. The official directions for purifying 
aloes are to melt 1000 Gm. of Socotrine aloes by means of a water-bath, 
and after addition of 200 Cc. of alcohol, to stir the mixture well and 
pass it through a No. 60 sieve which has been dipped into boiling 
water. The strained mixture is evaporated on a water-bath until a 
thread of the mass, upon cooling, becomes brittle ; it may then be 
preserved in lumps of convenient size in a cool, dry place. 

The process is strictly one of mechanical purification, the object 
being the removal of pieces of wood, leaves, aud other foreign matter 
usually found in socotrine aloes ; the alcohol is added simply to thin 
down the melted aloes and facilitate straining. By dipping the sieve 
into boiling water, chilling and adhesion of the mixture are avoided. 



270 PRACTICAL PHARMACY. 

Pel Bovis Purificatum, U. S. P. Fresh ox-gall contains considera- 
ble mucilaginous matter which, upon concentration of the former, 
renders the inspissated mass tough aud unmanageable; this can be 
removed with alcohol, and as liquid fresh bile is unfit for internal 
administration, purification is necessary. The Pharmacopoeia directs 
that fresh ox-gall be evaporated on a water-bath to one-third its 
volume, and then mixed with an equal bulk of alcohol and set 
aside in a covered vessel for three or four days ; the clear solution is 
then decanted, the remainder filtered, and the mixed liquids evapor- 
ated to a pilular consistence. 

A simple test of the quality of purified ox-gall is to dissolve it in 
water, when a clear solution should result which should remain trans- 
parent upon addition of an equal volume of alcohol. 



The Official Extracts. 

Of the thirty-two extracts recognized in the Pharmacopoeia, six 
are made with alcohol, Aconite, Indian Cannabis, Cimicifuga, Iris, 
Jalap, and Physostigma ; two are made with a mixture of alcohol 4 
volumes and water 1 volume, Podophyllum, and Rhubarb; three 
are made with a mixture of alcohol 3 volumes and water 1 volume, 
Cinchona, Leptandra and Nux Vomica (with addition of acetic acid); 
four are made with a mixture of alcohol 2 volumes and water 1 
volume, Belladonna Leaves, Digitalis, Euonymus, and Hyoscyamus ; 
six are made with diluted alcohol, Arnica Boot, Colocynth, Conium 
(with addition of acetic acid), Ergot (with addition of acetic acid), 
Stramonium Seed, and Juglans ; one is made with a mixture of alco- 
hol 2 volumes and water 5 volumes, Uva Ursi; eight are made 
with water, Aloes, Colchicum Boot (with addition of acetic acid), 
Gentian, Glycyrrhiza (with addition of ammonia water), Hcematoxylon, 
Krameria, Opium, and Quassia ; one is an inspissated juice, Taraxa- 
cum ; one, called a compouud extract, is made by mixing the several 
ingredients together and then powdering the mixture, Compound 
Extract of Colocynth. 



EXTRACTS. 



271 



Alphabetical List of Official Extracts, 

Showing the fineness of the powdered drug, the menstruum used, the required moisture, 
and the average yield. 



Name. 


Fineness 

of Menstruum. 
Powder. 


Quantity of 
menstruum 
to moisten 
1000 Gm. of 
the drug. 


Degree of 
Packing. 


Reserve. 


Average. 
Yield. 


Extractum— 

Aconiti . . . 


No. 60 Alcohol 


400 Cc. 


Firm 


900 Cc. 


20 per ct. 
50 " 


Arnicae Radicis 

Belladonnas ) 

Foliorum > 

AlcoholicumJ 


" GO Diluted Alcohol 

„ rn [Alcohol 2 vols. > 
60 {Water 1 « \ 

" 20 Alcohol 
" GO Alcohol 

f Alcohol 750 Cc") 

„ fi0 I Water 250 " 1 

ou 1 followed by diluted f 

1 alcohol J 

(Acetic Acid 350 Cc. ) 
"60 1 Diluted Alcohol 1500 " V 

(. followed by Water j 

" 20 Diluted Alcohol 

This Extract is a mixture of 160 par 
Aloes, 140 parts each of Resin of Sc 


400 " 

400 " - 

300 " 
250 " 

350 " 
500 " 


Firm 
Moderate 

r 
.; 


900 Cc 
900 " 


25 " 
20 " 

125* " 

15 " 
20 " 


CimicifugrE . . 









92 " 


Colocynthidis . 

Colocynthidis 
Compositum 


From 

pulp 

From 

pulp & 

seed 

500 parts 

parts of ( 


J 40 " 


ts Extract of 
ammony and 


i 

Colocynth, 
Soap and 60 


of Purified 
Cardamom. 



Conii . . . 
Digitalis . . 

Ergotoe . . 

Euonymi 

Gentianae 
Glycyrrhizas 

Pur una 
Hsenaatoxyli 

Hyoscyami . 

Iridis . . . 

Jalapas . . 

Juglandis . 

Kramerias . 

Leptandrse . 

Xucis Vomica? . 

Opii . . . j 
Physostigmatis 
Podophylli . . 



I Diluted Alcohol 980 " 
f Alcohol 2 vols. I 

1 Water 1 vol. J 

f Acetic Acid 20 Cc. |_ 

Diluted Alcohol 980 



300 Cc. 



900 Cc 20 per ct. 



850 Cc. 



•2.") 



j Extract of Ergot is officially directed to be made by simple evaporation 
I of the fluid extract 



No. 



2 vols. 
lvol. 



r Alcohol 
\ Water 

Water 
f Ammonia Water 150Cc 
\ Water 1000" 



400 Cc. 
400 " 

1000 " 



Rhei .... 

StramoniiSemin. 
Taraxaci . . . 

Uvae Ursi . . 



Rasped 


Water 








f Alcohol 
! Water 

followed by 


2000 CcO 




No. GO 


1000 " | 
diluted [ 


400 " 




[_ alcohol 




" 60 


Alcohol 




400 " 


" 60 


Alcohol 




350 " 


" 30 


Diluted Alcohol 


400 " 


" 40 


Water 




300 " 


" 40 


( Alcohol 
| Water 


3 vols. ") 
1 vol. | 


400 " 




( Acetic Acid 


50 Cc. ) 




" 60 


■\ Alcohol 


750 " y 


1000 " 




(Water 


250 " j 




Very fine 
powder 


t Water 






No. 80 


Alcohol 




400 " 


,; 60 


f Alcohol 
\ Water 


4 vols ") 


300 " 


1 vol. y 


" 20 


Water 




400 " 


" 30 


f Alcohol 


4 vols. ) 


400 " 




( \\ ater 


1 vol. / 





300 



No. 30 



Diluted Alcohol 

The official extract is an inspissated juice 
/Alcohol 2 vols, i 

j Water 5 " J 



400 Cc. 



















Firm 


900 Cc. 


(l 


900 Cc 











Firm 


900 Cc. 


" 


lOOOCc. 
900 Cc. 


" 


900 Cc. 



20 per ct. 

33 " 

20 " 

10 " 

24 " 

16 " 

13 " 

15 " 

12 " 



6 per ct. 
20 " 



272 PRACTICAL PHARMACY 

Special Remarks. 

Extractum Aconiti. If carefully prepared, this extract represents 
all the active principles of aconite root, in a very concentrated form; 
it is about five times as powerful as the root itself or the fluid extract, 
and should not be confounded with the extract of aconite of the 
British Pharmacopoeia, which is the inspissated juice of fresh aconite 
leaves, and a much weaker preparation. 

Extractum Aloes. Extract of aloes may be prepared from either 
Barbadoes or Socotrine aloes, the latter variety being generally pre- 
ferred in this country. The large proportion of water ordered by 
the Pharmacopoeia is for the purpose of avoiding the admixture of 
resin ; a concentrated aqueous solution of aloes retains in solution 
the resin present, whereas a dilute solution again deposits it on cool- 
ing. The extract does not yield a perfectly clear solution with water, 
as complete separation of resinous matter is impossible. The extract, 
when properly made, is brittle and is easily converted into a yellow 
brown powder. 

Extractum Belladonnce Foliorum Alcoholicum. This extract is of a 
deep brownish-green color and possesses a heavy narcotic odor. It 
is admirably adapted for incorporation in ointments and plasters, for 
which purpose it is usually softened with a few drops of water. The 
full official title of the extract is never used by physicians, the more 
familiar term Extractum Belladonnce being employed in prescription 
writing. In Great Britain, the name Extractum Belladonnce refers 
to the inspissated juice of fresh belladonna herb, and the name Ex- 
tractum Belladonnce Alcoholicum is applied to an alcoholic extract of 
belladonna root, a preparation more powerful than our own official 
extract; these differences must be borne in mind when compounding 
British prescriptions and other formulas. 

Extractum Cannabis Indicce. Extract of Indian hemp is not of 
uniform quality, owing to the variable character of the drug ; it is of 
blackish-green color and has a peculiar rather unpleasant heavy odor. 
The drug is rich in resin, which, together with the alkaloids present, 
is extracted completely by alcohol ; the extract is soluble also in 
ether, chloroform, oil of turpentine and fixed oils. Its alcoholic 
solution is precipitated by solution of potassa or soda, the resin 
being insoluble in alkalies. 

Extractum Qinchonce. With a little care, cinchona can be com- 
pletely deprived of its alkaloids by percolation with the official 
menstruum ; the extract, which is of a reddish-brown color, is apt to 
become tough in the course of time, and should be incorporated with 
10 per cent, of its weight of glycerin. The Pharmacopoeia makes 
no requirements as to alkaloidal strength, but, if made from choice 
bark, the extract may contain as much as 25 or 30 per cent, of total 
alkaloids, being from five to six times as strong as the drug itself. 

Extractum Colchici Radicis. The menstruum directed for this 
extract is of about the same strength as diluted acetic acid ; the extract, 



EXTRACTS. 273 

which is of brown color and bitter taste, is of a soft consistence, 
and cannot be rolled into pills by itself. The British extract and 
acetic extract of colchicum are both made from the fresh corm, in 
which condition it is said to be more active. 

Extr actum Colocynthidis. In order to avoid the fixed oil which 
is present in the seeds, the Pharmacopoeia directs that only the pnlp 
of the colocynth shall be used ; maceration and expression are pre- 
ferred to percolation, on account of the spongy character of the 
material. The yield of extract varies from 40 to 50 per cent, if 
made from good pulp; if calculated for the well-dried whole fruit, it 
ranges from 14 to 20 per cent. Many manufacturers allow the seeds 
to remain in the fruit, being careful not to have them crushed during 
the grinding. The presence of fixed oil in the extract would prevent 
evaporation to dryness and subsequent reduction to powder. 

Extr actum Colocynthidis Compositum. Since a perfectly homoge- 
neous preparation cannot be obtained by simply mixing the ingredi- 
euts in fine powder, the Pharmacopoeia very properly directs that an 
intimate mixture shall be effected with the aid of heat and alcohol ; 
when the alcohol has again been evaporated and the mass becomes 
brittle, the powdered cardamom is incorporated, and the vessel cov- 
ered until cold, so as to avoid loss of volatile oil. The dry com- 
pound extract is finally reduced to powder. It contains half its 
weight of purified aloes, 16 per cent, of dry extract of colocynth, 14 
per cent, each of soap and resin of scammony, and 6 per cent, of 
cardamom. 

Extractum Conii. This extract can be conveniently prepared by 
carefully evaporating the official fluid extract, in a porcelain dish, at 
a low temperature ; it is about five times as strong as the latter prep- 
aration. The herb and root of couium possess only very slight medi- 
cinal virtue, which latter resides in the volatile alkaloid ooniine. 
Extractum Conii of the British Pharmacopoeia is the inspissated juice 
of fresh conium leaves and branches, and a much feebler prepara- 
tion than our extract. Good extract of conium, when triturated 
with solution of potassa or lime-water, should evolve the disagree- 
able characteristic odor of coniine, in a marked degree resembling 
that of mice. 

Extractum Ergotce. Extract of ergot, prepared by evaporating the 
fluid extract, represents the crude drug in the proportion of about 1 
to 6, the yield from 150 Cc. of fluid extract being about 24 Gm. It 
is sometimes dispensed, under the name of ergotiu, in the form of pills 
and suppositories. Several of the European pharmacopoeias apply 
the name ergotin to a purified extract of ergot prepared by evapor- 
ating an aqueous infusion of ergot to a syrupy consistence and 
mixing with alcohol, whereby certain constituents (scleromucin and 
others) are precipitated ; after filtration the clear liquid is evaporated 
to a soft consistence. This was essentially the method of Bonjean, 
who first applied the name ergotin.to the extract of ergot made by 
himself in 1842. 

18 



274 PRACTICAL PHARMACY. 

The new Swiss Pharmacopoeia (1893), on the strength of the results 
following the investigations of Kobert and Keller, which prove that 
the medicinal virtues of ergot reside in the alkaloid cornutine, has 
adopted the following formula for preparing extract of ergot for 
hypodermic use. 1000 Gm. of powdered (No. 40) ergot are ex- 
hausted by percolation with 70 per cent, (by volume) alcohol ; the 
percolate is evaporated to 250 Gm., mixed with an equal weight of 
w r ater and filtered when cold. The residue is well washed with 
water and the liquid likewise filtered. 50 Gm. of 10 per cent, 
hydrochloric acid are added to the mixed filtrates and the mixture 
set aside for twenty-four hours ; after again filtering and washing 
the filter with water as long as the washings continue acid, 20 Gm. 
of crystallized sodium carbonate are gradually added. When the evo- 
lution of carbon dioxide has ceased, the liquid is evaporated to 1 50 
Gm. ; 15 Gm. of glycerin are then added, and the whole evaporated to 
125 Gm. All the alkaloid is retained in solution, while much useless 
matter, fixed oil, resin, coloring matter, etc., are removed ; a small 
amount of sodium chloride remains in the extract, but is not hurt- 
ful. The extract thus prepared is of the consistence of thick honey, 
and 1 Gm. represents 8 Gm. of ergot ; it forms a reddish-yellow, 
perfectly clear solution with water. 

Extractum Gentiance. All of the valuable bitter principles of gen- 
tian are soluble in cold water, while much inert matter is avoided by 
the use of this menstruum ; when hot water is employed the yield of 
extract is vastly increased on account of the large quantity of pectin 
compounds taken up. The object of boiling the cold water perco- 
late, as directed in the U. S. Pharmacopoeia, is to coagulate the albu- 
minous matter, after removal of which the extract obtained forms an 
almost clear solution with water. To judge from the tough condi- 
tion and imperfect solubility of many commercial extracts of gentian, 
manufacturers must frequently resort to heat in the exhaustion of the 
drug. With cold water, gentian yields about 30 per cent, of extract, 
which can be increased to 50 or 60 per cent, with hot water ; the 
United States, German, French, and Swiss Pharmacopoeias all direct 
cold water, but the British Pharmacopoeia, strange to say, recom- 
mends boiling for fifteen minutes, followed by expression. 

Extractum Glycyrrhizw Purum. The official formula for this 
extract yields a preparation perfectly soluble in water, which is not 
the case with the ordinary extract of commerce, in mass or powder. 
The addition of ammonia water to the menstruum insures, as already 
explained under fluid extract of liquorice root, the complete extrac- 
tion of the sweet principle, whilst the use of cold water prevents the 
solution of starch and much other inert matter. The yield of extract 
varies from 16 to 25 per cent. 

Extractum Hcematoxyli. The medicinal value of logwood lies in its 
astringent principle, which cannot be entirely extracted with cold 
water, hence boiling is officially directed. It is important that all 
contact with metal be avoided on account of the tannin, and the 



EXTRACTS. 275 

extract should yield a clear, purplish-red solution with water. Ex- 
tract of heematoxylon is well adapted for the dry condition, as it is 
non-hygroscopic ; its taste is sweetish and afterward astringent. The 
commercial extracts of logwood sold in boxes are not fit for medicinal 
purposes, being only partly soluble in cold water. 

Extraction Hyoscyami. The extracts of hyoscyamus of the British 
and German Pharmacopoeias must not be confounded with that offi- 
cially recognized in our Pharmacopoeia ; the former are the inspissated 
juice of the fresh flowering herb, more variable in quality than the 
hydro-alcoholic extract. Cubical crystals sometimes found in the 
British extracts of hyoscyamus and belladonna have, upon examina- 
tion, proved to be potassium chloride. 

Extraction Jalcqxe Jalap owes its valuable properties entirely to 
the resin it contains ; hence a purely alcoholic menstruum yields the 
most efficient extract. After jalap has been exhausted by alcohol, 
water will yet dissolve out a large proportion of extractive, which 
upon trial has been found perfectly inert. Jalap yields on an aver- 
age about 18 per cent, of alcoholic extract, and subsequently about 
30 per cent, of aqueous extract additional. The British Pharmaco- 
poeia directs the incorporation of the aqueous extract with the alcoholic 
extract first obtained ; hence the British extract is a much weaker 
preparation than our own. 

Extraction Kramerice. Cold water is an excellent solvent for the 
particular tannin present in rhatany, upon which the astringency 
of the drug depends; hot water will yield a larger percentage of 
extract, but this will not form a complete solution with water, while 
the cold water extract is soluble, and with the addition of sugar forms 
a perfectly clear liquid. A very weak alcoholic menstruum is said 
also to furnish an increased yield of extract, but with results similar 
to those produced by hot water. Decided astringency and a perfectly 
clear solution with warm water and sugar, are indications of a well- 
prepared extract. 

Extr actum Nucis Vomicae. The difficulties attending the perfect 
exhaustion of nux vomica have already been explained under the fluid 
extract. The seed contains considerable fixed oil, a portion of which 
is apt to be dissolved by the hydro-alcoholic menstruum; therefore, 
as the Pharmacopoeia directs the extract to be reduced to powder, the 
removal of the fatty matter becomes necessary. This is effected, as 
directed in the official formula, by concentrating the percolate to about 
15 per cent, of the weight of drug used and then washing repeatedly 
with ether as long as this removes anything. The ether is recovered 
by distillation and the fatty residue treated with boiling water and 
acetic acid, in order to recover any alkaloid which the oil may have 
carried with it. After the acid aqueous liquid has been added to 
the ether-washed residue, the whole is evaporated to a soft extract, 
cooled and weighed, after which the percentage of moisture and alka- 
loids is determined. From these data is calculated the quantity of 
sugar of milk which must be added to the soft extract, so that it 



276 PRACTICAL PHARMACY. 

can be dried and reduced to a fine powder containing 15 per cent, 
of alkaloids. 

Example : Suppose the soft extract contains 22 per cent, of 
moisture and 18.72 per cent, of alkaloids, how much sugar of milk 
must be added ? Answer : Each gramme requires the addition of 
0.468 Gm. of sugar of milk, or 100 parts require 46.8 parts. 

Calculation : 1.0 Gm. less 0.220 (22 per cent, of 1)= 0.780 Gm., 
the amount of dry extract obtainable from 1.0 Gm. of soft extract. 
Since no alkaloids are lost in drying, the percentage is increased 
from 18.72 per cent, in the moist to 24 per cent, in the dry extract, 
for 0.780:0.1872 = 1.0:0.24. 

The Pharmacopoeia requiring only 15 per cent, of alkaloids in the 
dry extract, the 0.780 Gm. must be brought, by addition of sugar of 
milk, to a weight of which 0.1872 Gm. shall represent 15 per cent., 
or in other words, 0.780 Gm. are equal to ^-f of the final weight of 
official powdered extract obtainable from 1.0 Gm. of the soft extract. 
The unknown final weight may be represented by x, whose value 
may be ascertained by solving the equation 0.15 : 1.0=0.1872 :x, 
or, if 0.780 = if of x, then »=|f of 0.780 ; in either case the value 
of x will be 1.248. 

Finally, 1.248 Gm. — 0.780 = 0.468 Gm., the weight of sugar 
of milk to be added. 

Extractum Opii. Opium is easily exhausted with cold water, but 
instead of triturating the mixture of opium and water occasionally 
during twelve hours, it is better to rub the opium into a smooth 
paste with water in a mortar, wash this carefully into a flask or 
bottle, add the remainder of the water, cork the flask or bottle, and 
shake vigorously every hour or two ; agitation is more easily accom- 
plished and is more beneficial to the extraction of the soluble prin- 
ciples. The magma on the filter should be slowly percolated with 
water until the liquid is uearly colorless and only faintly bitter. 
After concentration of the percolate to about twice the weight of 
opium used, the moisture and morphine present are determined, in 
order to ascertain the amount of sugar of milk which must be added 
to the syrupy extract, so that, upon complete drying, it shall yield 
a powder containing 18 per cent, of crystallized morphine. 

Example : Suppose the thick syrupy liquid is found to contain 72 
per cent, of moisture and 7 per cent, of crystallized morphine, how 
much sugar of milk must be added ? Answer : Each gramme will 
require the addition of 0.110 Gm. of sugar of milk. 

Calculation : 1.0 Gm. less 0.720 (72 per cent of 1) = 0.280 Gm., 
the amount of dry extract obtainable from 1.0 Gm. of the syrupy 
liquid. 0.07 Gm. (7 percent, of 1) of crystallized morphine present 
in 1 Gm. of the syrupy liquid, are equal to 25 per cent, in 0.280 Gm. 
of dry extract, as shown by the equation 0.280 : 0.07 = 1.0 : 0.25. 

The Pharmacopoeia requiring only 18 per cent, of crystallized 
morphine in the dry extract, the 0.280 Gm. must be brought, by 
addition of milk sugar, to a weight of which 0.07 Gm. shall repre- 



EXTRACTS. 277 

sent 18 per cent., or in other words, 0.280 Gm. is equal to JJ- of the 
final weight of official powdered extract obtainable from 1.0 Gm. of 
the syrupy liquid. The unknown final weight may be represented 
by x, whose value may be ascertained by solving the equation, 0.18 : 
1.0=0.07:*, or if 0.280 = if of; x, then a? = £f of 0.280; in either 
case the value of x will be practically 0.390 (actually 0.389). 

Finally 0.390 Gm. — 0.280 Gm. = 0.110 Gm., the weight of sugar 
of milk to be added. 

Extradural Quassice. This extract is prepared exactly like extract 
of gentian, and all the comments made upon the latter extract apply 
equally to this preparation. As extract of quassia is not used to 
any great extent, and is liable to become tough when old, the addi- 
tion of 10 per cent of glycerin to the extract, while still warm, is 
advisable. 

JExtractum Rhei. Extract of rhubarb presents the only instance, 
among the official extracts, in which the Pharmacopoeia directs that 
the reserve percolate shall be concentrated by spontaneous evapora- 
tion ; it is very questionable whether this plan is followed by manu- 
facturers. It is well known that the medicinal virtues of rhubarb 
are modified and sometimes injured by a high heat, but there can 
scarcely be any objection to the recovery of the alcohol from the 
reserve tincture, at a temperature below 50° C. (122° F.). The men- 
struum being strongly alcoholic (76 per cent.), the alcohol is readily 
volatilized. During the final evaporation of the extract to the pilular 
consistence, it is important that stirring with a glass or porcelain rod 
be assiduously kept up, otherwise granular separation of resinous 
matter will occur. 

JExtractum Stramonii Seminis. The reduction of stramonium seed 
to Xo. 60 powder is difficult, on account of the large proportion of 
fixed oil present, which also renders the preparation of a satisfactory 
extract no easy task. If the seed be first freed from oil, by treatment 
with benzin, much better results will be obtained. Stramonium oint- 
ment made from the official extract does not possess the green color 
characteristic of the ointment made from an extract of the leaves. 

JExtractum Taraxaci. As already stated, the Pharmacopoeia re- 
quires extract of taraxacum to be prepared from the fresh root; 
since the juice contains considerable albuminous matter which is not 
removed in the official process, the extract frequently becomes tough 
and imperfectly soluble. Much of the commercial extract of taraxa- 
cum is made from dried root, by percolation with water or a very 
weak alcoholic menstruum. True taraxacum root gathered in autumn 
is not always obtainable, and chicory root is frequently used as a 
substitute or as an adulterant. 

Extr actum TJvoe, Ursi. Although the Pharmacopoeia orders a mix- 
ture of 2 volumes of alcohol and 5 volumes of water as a menstruum 
for this extract, experience has shown that official diluted alcohol 
exhausts uva ursi completely and yields a more satisfactory prepara- 
tion. 



CHAPTEE XXIV. 

OLEOKESINS AND EESINS. 

Oleoresins. 

Solutions of this class represent the medicinal virtues of the 
drugs from which they are made, in a more concentrated form than 
is possible in any other. They possess the power of self-preser- 
vation, and in this respect are superior to fluid extracts. Oleoresins 
consist chiefly of fixed or volatile oils associated with resin and other 
constituents; those officially recognized in the Pharmacopoeia are all 
prepared by the same process, which consists in slowly percolating 
the drug in fine powder, with ether, to exhaustion, recovering the 
greater part of the ether by distillation, and finally removing the re- 
maining ether by spontaneous evaporation. The percolation of 
drugs with ether requires the use of special apparatus (see page 121) 
to prevent loss of the very volatile solvent, and several attempts have 
been made to economize ether by using the same liquid over again 
until the material is exhausted, the best device for this purpose 
being the ether-extraction apparatus designed by Prof. Fliickiger, 
illustrated in Fig. 203. The extractor, A, passes by means of the 
tube, D, through a cork into the receiving flask, E ; at Cis a septum 
or disk, upon w T hich the material to be extracted is packed, and which 
communicates, by means of a small funnel-shaped tube, with D. The 
lateral tube, B F, passes into the tube, G, which is provided with a 
properly cut cork, K, so that the ether vapor may pass from the re- 
ceiving bottle to a spiral condenser, If, fitted by means of a cork to 
the top of the extractor ; the ether vapor can also be made to pass up- 
ward through the powder, by pushing the cork deeper into the tube, 
G, thus closing the orifice of the lateral tube, B F. A loose pledget of 
cotton is placed in the funnel tube at C, or a piece of filtering paper 
is placed over the small opening, to prevent the material from passing 
down. The whole apparatus may be made of any convenient size, of 
glass or tinned copper, and when in use the receiving flask is placed 
in warm water, for the purpose of vaporizing the ether, which is 
condensed above the extractor and drops back upon the powder, the 
process being continued until the material is exhausted. Another 
desirable feature of this apparatus is the recovery of the ether from 
the marc when the extraction of the drug has been completed. The 
lateral communication between D and B F is closed by means of the 
cork, and, applying a cold or wet sponge to the receiving flask, the 
ether vapor therein is condensed and a partial vacuum produced, 
which withdraws all the ether from the marc in the percolator above. 



OLEORESINS AXD RESINS. 



279 



Fig. 203. 



Experience has shown that when 2 Cc. of percolate have been 
obtained for each gramme of drug used, the latter will be practically 
exhausted, therefore percolation beyond this 
point is unnecessary ; with the continuous 
extraction apparatus, half the quantity of 
ether can be made to accomplish the same 
results. 

Considerable care is necessary in the recov- 
ery of ether by distillation, as official ether, 
which is directed to be used in the process, 
boils at about 37° C. (98.6° F.) ; the recov- 
ered ether should be but very slightly impreg- 
nated with the odor of volatile oil, and may 
be used again for a subsequent operation. 
Oleoresins are not used to any great extent at 
present, and are rarely made by the pharma- 
cist himself; small quantities for use in pre- 
scriptions may be conveniently obtained by 
percolating some of the finely powdered drug 
in the barrel of a glass syringe and allowing 
the ether to evaporate in a warm place. The 
yield of oleoresin ranges from 5 to 60 per 
cent, for different drugs, and its consistence 
varies from liquid to a soft solid, dependent 
upon the amount of resin present. 

On account of the volatile and inflamma- 
ble character of ether, efforts have frequently 
been made to find a suitable substitute for the 
same ; mixtures of ether and alcohol have 
been tried, as also petroleum benzin, but not 
with general satisfaction. The experiments 
of Mr. G. M. Beringer, in 1892, with pure 
acetone, have, however, conclusively proven 
the value of this solvent. Acetone is a pro- 
duct of the destructive distillation of calcium 
or barium acetate, and is now available in a 
very pure state ; it is somewhat heavier than 
ether and boils at a point about 20° C. higher 
than that liquid. It is miscible in all propor- 
tions with water or alcohol, and possesses re- 
markable solvent properties. Drugs exhausted 
with acetone, when subsequently percolated 
with ether, have been found to yield nothing 
of value, and the oleoresins prepared with 
acetone are perfectly soluble in ether or alco- 
hol and practically identical with those made 
with ether. 

The Pharmacopoeia recognizes six oleoresins 
prepared with ether, and, in every case, with one exception, the drug 



<GM 



B 



FK 



D 



Fliickiger's Extraction 
Apparatus. 



280 



PRACTICAL PHARMACY. 



is packed firmly into the percolator, previous moistening being quite 
unnecessary. On account of the large proportion of resin in lupulin, 
this drug must be packed lightly, otherwise the mass will become im- 
pacted. The following is an alphabetical list of the official oleoresins, 
showing the fineness of powder used and the average yield. 



Name. 


Fineness of Powder. 


Average Yield 


Oleoresina Aspidii 


. No. 60 


15 per cent 


Oleoresina Capsici 


" 60 


12 


Oleoresina Cubebse 


" 30 


22 


Oleoresina Lupulini 




60 


Oleoresina Piperis 


'. 60 


6.5 " 


Oleoresina Zingiberis 


" 60 


6 



Special Remarks. 

Oleoresina Aspidii. This preparation is also known by the names 
oleoresina jilicis, extraction jilicis cethereum, and oleum jilicis maris. 
As the root rapidly deteriorates upon keeping, only that having a 
fresh green color should be used. The oleoresin of male fern gen- 
erally deposits, on standing, agranular crystalline substance largely 
composed of filicic acid, upon which depends the activity of the 
preparation, hence the necessity for thoroughly incorporating the 
deposit before dispensing the oleoresin. By percolation with acetone 
the drug has yielded as much as 18 per cent, of oleoresin. 

Oleoresina Capsici. Owing to the large amount of fat present in 
capsicum, it is not desirable to carry percolation to complete exhaus- 
tion ; experience, in fact, has taught that, if collected slowly, 150 Cc. 
of percolate will have practically exhausted 100 Gm. of the drug, and 
that further treatment simply loads the percolate with fatty matter. 
Oleoresin of capsicum is a dark, brownish -red liquid, which, shortly 
after being made, deposits granular fat ; this is best removed by 
decanting the clear liquid and straining the residue, or washing the 
deposit rapidly with a little ether. Although the average yield of 
oleoresin has been reported as not over 5 or 6 per cent., from 12 to 
16 per cent, of a very excellent preparation has frequently been 
obtained. 

Oleoresina Cubebm. Cubeb yields all its medicinal virtues to alcohol 
as well as ether ; very satisfactory oleoresin has been made with the 
former menstruum. In Germany, the oleoresin is officially recog- 
nized under the name "Extr actum Cubebarum" and is prepared with 
a mixture of equal volumes of ether and alcohol. All oleoresin of 
cubeb deposits, upon standing, waxy matter and a crystalline body, 
cubebin, which, as the Pharmacopoeia directs, should be rejected, only 
the liquid portion being dispensed. It is of a green or brownish- 
green color, and, when made with acetone, has been obtained to the 
extent of 25 per cent. 

Oleoresina Lupulini. Lupulin is very rich in resin, hence a large 
yield of oleoresin is to be expected ; it is of a reddish-brown color 
and has the consistence of a soft solid extract. While the average 



OLEORESINS AND RESINS. 281 

yield is about 60 per cent., as much as 70 per cent, has been obtained 
with both ether and acetone, by complete exhaustion. 

Oleoresina Piperis. Commercially this preparation is also known 
as oil of black pepper, which latter, however, is usually obtained as a 
by-product in the manufacture of piperiu. Oleoresin of pepper, when 
first made, deposits piperin in crystalline form, which is separated by 
straining, leaving a thick, very black liquid. The yield with ether 
or acetone rarely exceeds 6 per cent. 

Oleoresina Zingiberis. When made from uncoated (Jamaica) ginger 
the yield of oleoresin is less than from coated ginger, and is also 
lighter in color, thinner, and of a more agreeable flavor. The name 
piperoid has sometimes been applied to this preparation. From 
coated ginger as much as 10 per cent, of oleoresin has been obtained, 
while from Jamaica ginger the yield rarely exceeds 6 per cent. 

Resins. 

Under the title Resina? the Pharmacopoeia recognizes five prepa- 
rations, two of which, however, are simply residuary products 
obtained in the distillation of the volatile oil from natural oleoresins. 
For the remaining three an official process of manufacture is given, 
alcohol being used as a solvent in each case ; the resin is obtained by 
pouring a concentrated alcoholic tincture of the respective drugs into 
cold water and subsequently washing the precipitate repeatedly with 
water. 

Alphabetical List of the Official Eesins. 

Official Name. How obtained. 

Resina Residue left after distillation of the volatile oil from Turpentine. 

Resina Copaibse Residue left after distillation of the volatile oil from Copaiba. 
Resina Jalapse By pouring a concentrated alcoholic tincture of Jalap into cold 

water. 
Resina Podophylli By pouring a concentrated alcoholic tincture of Podophyllum 

into cold water acidulated with hydrochloric acid. 
Resina Scammonii By pouring a concentrated alcoholic tincture of Scammony into 

cold water. 

Special Remarks. 

Resina Jalapce. The amount of resin in jalap root varies consid- 
erably, rangiug from 8 to 18 per cent., and it is not always possible 
to find commercial jalap which meets the official requirement of not 
less than 12 per cent. Resin of jalap differs from the official extract 
of jalap, in being free from water-soluble matter, of which the latter 
preparation contains quite an appreciable quantity ; hence the official 
direction, to wash the precipitated resin twice with water, should be 
repeated until the washings are colorless ; the adhering water is re- 
moved by drying the resin with a gentle heat. Not more that 10 
per cent, of the resin of jalap should be soluble in ether, nor more 
than 7 per cent, in chloroform. The presence of common resin may 



282 PRACTICAL PHARMACY. 

be detected by solubility in oil of turpentine and by gelatinization 
upon cooling a solution made by digesting the suspected resin in 10 
parts of ammonia water at 80° C. (176° F.). Since resin of jalap 
has a slightly acrid but not bitter taste, an adulteration with aloes 
may be suspected if a pronounced bitter taste is observed. If resin 
of jalap be moistened with alcohol and then with a solution of ferric 
chloride, a green color should not be developed, nor should a blue 
color be observed if the inner surface of a fresh potato paring be 
rubbed with the resin, otherwise guaiac is present. That portion of 
jalap resin insoluble in ether, when dissolved in caustic alkali solu- 
tion, is not reprecipitated upon addition of an acid ; this property 
distinguishes jalap resin from other resins except that of scammony, 
and from the latter it differs by its insolubility in ether and oil of 
turpentine. While resin of scammony might become accidentally 
mixed with jalap resin, it would never be added as an adulteration, 
since it is far more expensive. 

Resin of jalap may be obtained free from color, by treatment with 
animal charcoal ; the best plan is to mix the charcoal with the pow- 
dered jalap before percolation and also to pass the percolate through 
animal charcoal. 

Resina Podophylli. The object of adding hydrochloric acid to the 
water, before adding the alcoholic solution, is simply to facilitate the 
separation of the resinous matter. The yield of resin of podophyllum 
rarely exceeds 4 or 5 per cent., and its color should be from grayish- 
white to yellowish-green, provided no heat higher than 35° C. (95° F.) 
is used in drying it. According to Prof. Lloyd, who has had large 
experience in the manufacture of this resin, the concentration of the 
alcoholic tincture should not be carried beyond a very thin syrup, 
the water into which it is poured should be ice-cold, and the washed 
resin should be dried tcithout heat, by exposure to air, in a cold place. 
Alum water is sometimes used to effect precipitation of the resin, but 
it yields a yellow product of inferior quality. The solubility of resin 
of podophyllum in ether varies from 50 to 85 per cent., depending 
upon the mode of its preparation, the better quality being most 
soluble and also lighter in color ; according to Prof. Power, boiling 
water will dissolve about 80 per cent, of the resiu if the treatment 
with fresh portions of the water be continued as long as anything is 
removed, but deposits most of it again on cooling. Resin of podo- 
phyllum forms a yellow liquid with solution of soda or potassa, 
from which it is re-precipitated by acids. 

The name podophyllin is extensively applied in commerce to the 
resin, but does not always represent the official article. 

Resina Scammonii. The Pharmacopoeia directs that this resin 
be prepared from the gum-resin scammony and not from the root 
direct, as in the two preceding resins ; hence treatment of the 
powder with boiling alcohol is directed instead of percolation. The 
yield of resin of scammony depends upon the quality of the gum- 
resin, and may vary. from 70 to 90 per cent., alcohol taking up 



OLEORESINS AND RESINS. 283 

only about 2 per cent, of water-soluble matter, according to Prof. 
Markoe. 

Resin of scammouy is wholly soluble iu ether and oil of turpen- 
tine, and is not precipitated by acids from its solution in caustic 
alkalies. • It is very slowly acted upon by sulphuric acid, whereas 
common resin is immediately turned intensely red ; the presence of 
the latter can thus be detected. The resiu of scammony can be distin- 
guished from the gum-resin by not yielding a green emulsion when 
triturated with water. 



CHAPTER XXY. 

COLLODIONS. 

Under this head are recognized in the Pharmacopoeia four solu- 
tions, the base of which is pyroxylin, or soluble gun-cotton (see Cel- 
lulose, Part III.), and the solvent, a mixture of alcohol and ether. 
Collodions are employed only for external medication, and owing to 
the very volatile character of the solvent, they rapidly form a skin- 
like covering, or pellicle, when applied, which is impervious to water. 
Where a strong contractile coating is desired, the plain collodion is 
preferred, otherwise a less constringent and more comfortable cover- 
ing is obtained by the addition of castor oil and Canada turpen- 
tine, as in the case of the official flexible collodion. For the purpose 
of medication, any substance soluble in ether may be added, such as 
iodine, iodoform, extract of Indian cannabis, salicylic acid, croton 
oil, mercuric chloride, veratrine, atropine, resorcin, pyrogallol, etc. 
Since pyroxylin is insoluble in water, the addition of the latter to collo- 
dion would cause immediate precipitation, hence all substances soluble 
only in water or alcohol and water, such as extract of belladonna, 
morphine sulphate, etc., are excluded from admixture. Collodions 
should always be preserved in tightly cork-stoppered bottles, in a 
cool place, remote from fire, on account of the ether present; care 
should also be taken that no collodion be allowed to remain on the 
lip or in the neck of the bottle after pouring out the liquid, to avoid 
"fixing" of the cork as the menstruum evaporates. 

Collodions are best dispensed in small, round-shouldered vials pro- 
vided with a cork through which a camel-hair pencil has been passed 
and securely fastened ; this avoids loss of material and drying of the 
collodion in the brush — a very annoying occurrence. 

Alphabetical List or Official Collodions. 

Official Name. Composition. 

Collodium Pyroxylin, 3 6m. ; Ether, 75 Cc. ; Alcohol, 25 Cc. 

Collodium Cantharidatum Chloroformic Extract of Cantharides (representing 

60 Gm Cantharides), 15 6m ; Flexible Collodion, 
85 Gm. 

Collodium Flexile Castor Oil, 3 Gm. ; Canada Turpentine, 5 Gm. ; Col- 

lodion, 92 Gm. 

Collodium Stypticum Tannin, 20 Gm. ; Alcohol, 5 Cc. ; Ether, 25 Cc. ; Col- 

lodion, sufficient to make 100 Cc. 

Special Remarks. 

Collodium. If the pyroxylin has been carefully prepared, it should 
be perfectly soluble in the official menstruum, although a slight sedi- 



COLLODIOXS. 285 

merit of dirt, etc., occurs after the solution has been set aside for a few 
hours ; from this the liquid can be carefully poured off, as filtration 
is impracticable. Anthony's collodion cotton, specially prepared for 
photographers' use, I have always found very satisfactory. 

Collodium Canthari datum. The value of cantharidal collodion 
will depend upon the quality of the powdered cantharides used and 
the care with which they are exhausted. Since chloroform is a very 
volatile menstruum, percolation must be conducted in a special appa- 
ratus (see Oleoresins), to avoid loss ; the liquid is easily recovered by 
distillation on a water-bath, as chloroform boils at about 60° C. 
(140° F.). The extract dissolves readily in flexible collodion, by 
agitation, the finished product representing 60 per cent, of its weight 
of powdered cantharides, which makes it nearly twice as strong as 
the official cerate of cantharides. 

Collodium Flexile. The addition of Canada turpentine (Canada 
balsam or balsam of fir) and castor- oil lends to collodion the pro- 
perty of forming a flexible pellicle which, while serving as a perfect 
covering to the part affected, yet permits perfect freedom of motion. 

Collodium Stypticum. Owing to the large proportion of tannin 
ordered in the formula for styptic collodion, it is necessary to use a 
small quantity of diluent, ether and alcohol, with which the tannin 
is thoroughly mixed before the final addition of collodion. Flexible 
collodion is not suitable in this case, as a constringent pellicle is desired. 
Any impurities from the tannin, may be removed by rapidly strain- 
ing the solution through gauze previously moistened with a little 
ether and alcohol. 



CHAPTEE XXVI. 

EMULSIONS. 

The term " emulsion " is applied to a more or less permanent 
homogeneous liquid mixture composed of fatty, ethereal, or resinous 
substances and water, the former being suspended in a minutely 
divided state, which gives rise to the peculiar opaque and milk-like 
appearance. Nature provides types of true emulsions, in the form 
of milk, the natural food of all young mammalia, and the milk-like 
juices of certain plants from which the official and other gum-resins 
are obtained. 

Those prepared by pharmacists, may be conveniently divided 
into natural and artificial emulsions ; to the former class belong 
those which are made from seed or gum-resins, by simple tritura- 
tion with water, Nature having provided the necessary emulsifying 
agent in intimate association with the oil or resin. Artificial emul- 
sions are such as require the addition of some foreign body, by means 
of which the suspension of the oil or resin is made possible ; to this 
class belong the majority of the emulsions prepared at the dispensing 
counter. Fixed and volatile oils, as well as ether, chloroform, oleo- 
resins and resins, are suitable for exhibition in the form of emulsion, 
the suspension in water being accomplished by the aid of appro- 
priate excipients, such as acacia, tragacanth, yelk of egg, casein, 
dextrin, Irish moss, gelatin, soap-bark, etc. Oil-yielding seeds and 
natural gum-resins contain albuminous and mucilaginous matter, by 
means of which the oil and resin can be brought into perfect sus- 
pension in water, and such emulsions approach more closely in char- 
acter and stability to cow's milk, which may be looked upon as the 
most perfect emulsion known. The theory of emulsification is as 
follows : The insoluble liquid or solid, in a state of minute division, 
is completely surrounded or enveloped by the vehicle consisting of 
water and excipient, and thus an opaque mixture is produced, from 
which, the particles cannot separate by mere force of cohesion ; such 
a condition can be obtained to perfection only by choice of a proper 
excipient, and, for artificial emulsions, none better than acacia has yet 
been found. Stability of artificial emulsions, while primarily de- 
pendent upon the division of the insoluble liquid into minute globules, 
is also influenced, to some extent, by the density of the vehicle, thus 
sugar has been found to increase the suspending power of gum mate- 
rially ; to prevent fermentative changes likely to arise in all aqueous 
vegetable solutions, alcohol or glycerin is frequently added to emul- 
sions, in the proportion of one or two fluidounces for every pint. 



EMULSIONS. 287 

With the exception of those made of volatile oils or ethereal 
liquids, emulsions should always be made iu a mortar, either of 
unglazed Wedge wood or hard porcelain, having a flat bottom, and, 
in the case of seed or gum-resin emulsions, oue of deep shape pro- 
vided with a hard-wood pestle is to be preferred, in order to avoid 
injury from the force often necessary in crushing and manipulating 
the material. For making gum-resin emulsions, the cleanest and best 
tears should be selected, as the commercial fine powders are unfit for 
this purpose, partly because they are inferior in quality, and partly 
because they have been so modified by drying that when triturated 
with water they simply form an ordinary mixture from which the 
powder separates rapidly on standing ; this change is due to dehydra- 
tion, whereby the natural association of gum and resin has been 
broken up and their intimate union destroyed. For seed emulsions, 
when no other proportions are specified, 1 part of seed is used to 10 
parts of water, all dirt and dust being carefully removed, if neces- 
sary, by w ashing with cold water. In both cases the material is 
crushed into a coarse powder, and, after the addition of a small quan- 
tity of water, beaten into a perfectly smooth pasty mass ; to this, 
the remainder of the water is then added in divided portions, tritu- 
rating the mass thoroughly and keeping it well scraped down from 
■the pestle and sides of the mortar, so that a uniform mixture may 
result, which is finally passed through a well-wetted strainer of loose 
flannel or cheese-cloth, to remove the inert woody fibre and possible 
impurities. In making emulsion of lycopodium, it becomes neces- 
sary to triturate the seed dry y with some pressure, in order to rupture 
the hard seed envelope ; when the powder changes in color and be- 
comes damp and adhesive from the oil, a little water is added, with 
which a smooth soft paste can be formed, to be further diluted by 
the addition of water as directed above. Emulsion of lycopodium 
should never be strained, and, if properly made, will show no particles 
floating on the surface ; the insoluble matter which settles upon 
standing is readily reincorporated by agitation. 

Oil emulsions, which are far more frequently used (at least in this 
country) than those made from seed or gum-resius, require more 
care in their preparation, as success depends not only on the manipu- 
lation, but also on the judicious choice of a proper excipient. As a 
general rule, it may be stated that acacia produces the whitest and 
most stable emulsions, because its perfect and ready solubility in 
w 7 ater, enables the operator to divide the oil quickly into minute 
globules, which are at once surrounded by an envelope of the muci- 
laginous liquid aud thus kept from coalescing. The oil globules of a 
well-made acacia emulsion, when compared with milk under a magni- 
fying lens more closely resemble its fat globules than would be the case 
if made with other excipients. To insure success, it is essential that 
definite proportions of oil, gum, and water be used for making the 
primary emulsion, which can then be diluted with water as desired. 
Not less than one-fourth nor more than one-Jtalf as much acacia as oil 



288 



PRACTICAL PHARMACY. 



Fig. 204. 




should be used, and not less than one and a half times nor more than 
twice as much water as acacia. The mixing of oil, gum, and water 

should not be effected by the usual 
method of trituration, w T hich involves 
pressure of the pestle against the ma- 
terial on the bottom and sides of the 
mortar, and consequent development of 
heat, but should be brought about by 
a rapid light rotary movement of the 
wrist, communicated to the pestle held 
loosely in the hand, as shown in Fig. 
204 ; this motion partakes more of that 
of an egg- whip, and the oil is thus rap- 
idly broken up into minute globules in 
the presence of a viscid solution. 

As stated before, emulsions of fats 
and fixed oila are best made in a flat- 
bottomed mortar, three distinct methods 
being in use to effect the desired ob- 
ject : namely, a milk-like liquid, mis- 
cible with water without the separation 
of oil globules. By many pharmacists 
the method usually recommended in Great Britain is preferred; this 
consists in making a smooth thick mucilage of granulated acacia and 
water, and then adding the oil by degrees, stirring assiduously until 
each portion of oil is emulsified — lastly adding the water for dilu- 
tion, in divided portions. The other two are sometimes called the 
" Continental" methods, from the fact that they are used almost 
exclusively in Continental Europe. They do not direct the previous 
solution of the gum in water, and adhere strictly to definite propor- 
tions. While the so-called " English " method yields very satisfactory 
results in the hands of those accustomed to it, I much prefer, for the 
inexperienced, either of the other two methods, my preference being 
based upon observation of many hundred cases in the hands of 
students working in the laboratories. I have never known of a 
single failure by a novice to make a perfect emulsion according to 
the following methods, provided of course that the directions as given 
were followed. 

Place in a mortar one-fourth as much finely powdered acacia as 
the oil to be used (7.5 Gm. of acacia for 30 Cc. of oil, or 5ij for 
f'Sj), then add the oil and triturate well together into a smooth mix- 
ture. Now add all at once, not gradually, twice as much water as the 
acacia which has been used (15 Cc. of water for 7.5 Gm. of acacia, or 
f5iv for 5ij), and stir rapidly until a perfect emulsion has been 
formed, which is known by the appearance of a white pasty mass, 
free from oil particles, and a peculiar crackling noise as the pestle 
is drawn through the adhesive mixture. This primary emulsion 
should be well scraped down with a spatula from the pestle and sides 



EMULSIONS. 289 

of the mortar, again stirred, and then the remainder of the water 
slowly added with constant stirring. Granulated acacia cannot be 
used in this method, as with so small a quantity of gum it is neces- 
sary that it dissolve almost immediately, which will not occur with 
the granulated variety. 

The second of the so-called " Continental " methods directs in- 
creased proportions of acacia and water, by which means an equally 
perfect, and at the same time denser, primary emulsion is obtained. 
One-half as much granulated acacia as oil is used, and one aud a half 
times as much water as gum, or one-half as much water as oil and 
gum together; thus, oil 30 Cc. or f5j, granulated acacia 15 Gm. or 
5iv, and water 22.5 Cc. or fovi. Place the acacia in a dry mortar, 
add the oil and water, and stir briskly until a perfect emulsion results, 
which dilute with the remaining water, as in the preceding method. 

If from any cause the primary emulsion should fail, it will prove 
a loss of time and labor to endeavor to save it by addition of gum 
or water, provided the right proportions were used in the first place ; 
the best plan is to begin over again and observe care in details. 
Assiduous stirring or shaking is of no avail in trying to save a 
" cracked " emulsion, which has a pearly appearance in the mortar, 
and the further addition of gum, while increasing the density of the 
mixture, does not always remedy the trouble. 

The above methods are equally well adapted for liquid oleoresins, 
such as copaiba, oleoresin of cubeb, etc. If solid fats, camphor, some 
oleoresins and resinous extracts, as, for instance, extract of Indian 
cannabis, are to be administered in aqueous liquids, it will be found 
advantageous to dissolve them in a small quantity of fixed oil (oil of 
sweet almond or olive oil), aud then to emulsify them in the manner 
directed for these oils. Salol, menthol, thymol, phosphorus, and 
other substances, can likewise be conveniently emulsified after solu- 
tion in some fixed oil. The emulsification of Peru balsam will be 
materially facilitated by the addition of a little alcohol or oil of 
sweet almond, about 10 per ceut. of the volume of balsam being 
sufficient. If emulsions of wax or spermaceti are to be made, heat 
must be employed ; the wax or spermaceti is melted in a mortar 
heated to about 6o° C. (149° F.) and mixed with an equal w r eightof 
powdered acacia, after w T hich, exactly one and a half times as much 
water as acacia, heated to near boiling, is added, and the mixture 
briskly stirred. After the emulsion cools to about 30° C. (86° F.), 
more water may be added in small quantities, with constant stirring. 
Whenever double emulsions are ordered, as, for instance, a seed emul- 
sion with that of a fixed oil, better results will be obtained if separate 
emulsions be made and then mixed ; when castor oil is to be mixed 
with emulsion of almond as a vehicle, the oil should be emulsionized 
w r ith the requisite quantity of acacia and water, and this primary 
emulsion then diluted with the almond emulsion, out of which the 
water necessary for the previous emulsification of the oil has been 
retained. 

19 



290 PRACTICAL PHARMACY. 

Whenever an oil emulsion is made, the rule should be observed 
never to measure the water in an oily graduate, as otherwise oil 
particles might be subsequently carried into the mixture, and, 
failing to be emulsified, eventually rise to the surface. The view 
held by some authorities, that a good emulsion is capable of emul- 
sifying additional quantities of oil, requires modification, as already 
pointed out by Mr. Gerrard, of England ; for, although a perfect 
fixed-oil emulsion admits of the incorporation of more oil, this latter 
oil will not undergo emulsification, but be simply intimately mixed, 
as can be proven by the addition of water, when the newly added 
oil will separate. A perfect artificial emulsion should have a milk- 
like appearance and consistence, be miscible with water without 
separation, should flow readily from the mortar without leaving any 
adhering particles, so that it can be washed with plain water, and, if 
separation takes place after standing at rest for some time, a cream- 
like layer should rise to the surface, which can be quickly reincorpo- 
rated by agitation. Heat is detrimental to the permanence of emul- 
sions and causes separation, so also large quantities of alcohol or saline 
matter. Substances which have a tendeney to absorb water, such as 
magnesia, must not be mixed with the emulsion, unless previously 
completely hydratecl. All salts should be added in the form of solu- 
tion, and together with tinctures and other alcoholic liquids, not 
until the primary emulsion has been properly diluted. 

Emulsions of ether, chloroform, oil of turpentine, and other 
volatile liquids, are best prepared by agitation in a bottle after the 
manner first suggested by Forbes. The liquid to be emulsiouized is 
poured into a perfectly dry bottle and the powdered acacia added, after 
which the bottle is well shaken so that the acacia may become satu- 
rated with the volatile liquid ; water is then added and agitation 
continued uutil a homogeueous emulsion results, which can be further 
diluted by the gradual addition of water. Volatile oils and ethereal 
liquids will never form as perfect an emulsion as fixed oils, and 
separation of the mixture takes place more speedily ; if care has been 
observed, however, in making the mixture, only a dense creamy layer 
will rise to the surface, which can be reincorporated by agitation. 
As a rule, volatile oils and ethers require more gum than fixed oils, 
and less than 30 grains of powdered acacia should not be used for 
each fluidrachm; the amount of water first added should always 
be equal to twice the acacia used. Oil of turpentine unites very 
readily with water and gum, and it is surprising to see how small a 
quantity of gum will suffice to form a perfect emulsion from which 
no oil will separate in an uncombined form, only a dense creamy 
layer rising, composed of the oil of turpentine, gum, and some 
water in intimate union; 20 grains of powdered acacia shaken in a 
bottle with 1 fluidounce of oil of turpentine, and 4 fluidrachms of 
water then added, will yield a very satisfactory emulsion, which can 
be kept for days without separating an oily layer. All emulsions of 
volatile oils are more permanent if made with the aid of some fixed 



EMULSIONS. 291 

oil previously added to the volatile oil; such emulsions are preferably 
made in a mortar. 

"When powdered tragacanth is preferred as an emulsifying agent, it 
may be used in the proportion of one- tenth or one-eighth of the neces- 
sary weight of acacia, and requires from 10 to 20 times its weight of 
water ; it should be thoroughly mixed with the oil in the mortar or 
bottle, as the case may be, and after the addition of water the mixture 
should be rapidly stirred or shaken until the primary emulsion has been 
formed. The division of oil globules by meaus of mucilage of traga- 
canth is much coarser than with acacia, hence tragacanth emulsions 
are never so white nor seemingly so perfect ; but owing to the viscosity 
and magma-like condition of mucilage of tragacanth, the oil globules, 
although not finely divided, are kept from re-uniting, and thus separ- 
ation of an oily layer is prevented. Mixtures of tragacanth and 
acacia are often employed, particularly in the em unification of cod- 
liver oil, to obtain greater protection against separation. 

Yelk of egg has long been known as a valuable excipient in emul- 
sions, particularly when acids or large proportions of alcoholic liquids 
are to be added. One yelk from an egg of average size will suffice 
for 1 fluidounce of a fixed oil or for J- fluidounce of a volatile oil ; 
in place of the simple yelk, the official glycerite of yelk of egg, also 
known as glyconiu, of which J fluidounce is necessary for an ounce 
of fixed oil, has been used with decided advantage. In either case 
the oil should be added in small quantities to the yelk of egg or 
glyconin, previously rubbed smooth in a mortar, each portion being 
thoroughly incorparated before another addition is made ; if the mix- 
ture should become inconveniently thick, a small quantity of water may 
be introduced, and after all the oil has been emulsified the prescribed 
amount of water is added, likewise in divided portions, with constant 
stirring. The readiness with which yelk of egg unites with fixed 
oils is due to the fact that it is itself a natural emulsion of an oil 
and albuminous matter. Some little care is necessary in removing 
the yelk of egg from the shell, to avoid contamination with the white 
or albumen, which has a tendency to form clots in the emulsions. 

Among other emulsifying agents introduced during the last ten 
years, none has been more extensively used, particularly on a large 
scale by manufacturers, than mucilage of Irish moss. Toward fixed 
oils the mucilaginous matter of Irish moss behaves somewhat like 
tragacanth, particularly if the solution of the former be made some- 
what thick. This mucilage is made by washing the drug with cold 
water to remove saline and other foreign matter, then heatiug it with 
the required quantity of water in a dish, for fifteen minutes, on a 
boiling water bath, and fiually straining the mixture; the strength 
of the mucilage may be from 10-15 grains to the ounce, that of the 
National Formulary being 12 grains. Of the latter mucilage, 1 fluid- 
ounce is considered sufficient for 1 fluidounce of oil, the emulsion 
being made by adding the oil in small portions to the mucilage con- 
tained in a bottle and agitating briskly after each addition ; after all 



292 PRACTICAL PHARMACY. 

the oil has been emulsified, syrup or more water may be added as a 
diluent. Emulsions made with Irish moss are not so white as those 
made with acacia and contain the oil in a coarser state of division ; 
some manufacturers add acacia to the Irish moss mucilage, in order 
to improve the emulsion. 

While milk itself is a very poor emulsifier of fats and fixed oils, 
its albuminoid constituent, casein, is said to be even superior to acacia. 
According to Leger, a French pharmacist, it is best used in the form 
of a saccharated powder, prepared as follows : To 4 quarts of milk 
warmed to 40° C. (104° F.) add 2J fluiclouuces of ammouia water, 
and after setting aside for twenty-four hours, withdraw the lower milk- 
serum from the upper fatty layer. Precipitate the caseiu from the milk- 
serum by addition of acetic acid, and wash the precipitate by decan- 
tation with water warmed to about 40° C. (104° F.) ; finally collect 
on a wetted muslin strainer and express the moisture. Determine 
the amount of dry casein in the residue by heating a weighed portion 
to complete dryness in an air-bath ; add 10 grammes of sodium bicar- 
bonate and sufficient sugar to obtain, when dry, a powder containing 
10 per cent, of its weight of casein. The mass must be dried at a 
gentle heat and powdered ; it keeps well for a long time in securely 
corked bottles. For oil emulsions, Leger recommends the making of a 
mucilage of 15 parts of saccharated casein with 5 parts of water, and 
adding to this in small portions 15 parts of oil, stirring well after 
each addition; finally diluting the emulsion as required. 

Condensed milk has also been successfully used as an emulsifying 
agent for castor oil and cod-liver oil. A fluidounce of the oil is 
mixed by trituration in a mortar, in small quantities, with one-half 
fluidounce of condensed milk, and, when emulsified, one-half fluid- 
ounce of water is slowly added, with constant stirring. Such emul- 
sions, however, do not bear dilution well. 

Another emulsifying agent, recommended as a substitute for acacia 
by some pharmacists, is mucilage of dextrin, to be used in the pro- 
portion of 5 or 6 fluidrachms to 1 fluidounce of fixed oil. The 
mucilage, according to the National Formulary, is made by heating 
1 ounce of white dextrin with 2 ounces of water to near boiling until 
the dextrin is dissolved ; any loss of water by evaporation is made up 
so that the product weighs 3 ounces ; when the mucilage has cooled 
short of gelatinizing, it is ready for use in the same manner as muci- 
lage of Irish moss. 

The saponaceous principle of quillaja possesses the property of 
dividing and suspending oil globules quite well if used in sufficient 
quantity. The official tincture of soap-bark may be employed in the 
proportion of 2 fluidrachms for each fluidounce of fixed oil, or of one- 
half to one fluidounce for each fluidounce of volatile oil, but owing 
to the irritant properties of quillaja, it must be used with care, and 
therefore cannot be recommended for use indiscriminately. 

For making from one to five gallons of emulsion, the apparatus 



EMULSIONS. 



293 



known as the Morton Patent Egg-Beater or Whisking Machine, 
illustrated in Fig. 205, has been found very serviceable and satisfac- 
tory ; it is made of heavily-tinned iron, and supplied with a water- 
chamber underneath, by means of which either hot or cold water may 
be employed for tempering, whenever desired. The upper tank is 
provided with a rounded bottom, and the emulsification is effected 
by means of several heavy wire beaters in circular form revolving 
rapidly in opposite directions within each other, whereby constant 
cross-cutting of the mixture and most perfect dashing of the con- 
stituents is insured ; to prevent dust from entering, the tank is pro- 
vided with a well-fitting top. The beaters are easily removed by 
withdrawing the frame, and the apparatus can be quickly and 
thoroughly cleaned. 

Fig 205. 




The Morton Patent Egg-Beater. 

When emulsions are to be made on a large scale, the usual plan is 
to add the oil, in a thin continuous stream, to the mucilage contained 
in , a suitable churning apparatus operated by steam power, the 
mixture being kept in constant agitation by rapidly revolving 
metallic blades frequently provided with numerous perforations. In 
this way, 10 or 15 gallons of oil can be completely emulsified in the 
course of a day. 

The Official Emulsions. 

The Pharmacopoeia recoguizes four emulsions : one made from 
seed, two from gum-resins and one containing chloroform together 
with a fixed oil. In each case specific directions are given for 
manipulation, which agree with those explained elsewhere. 



294 



PRACTICAL PHARMACY. 



Alphabetical List of the Official Emulsions. 



Official Name. 
Emulsum Ammoniaci 
Emulsum Amygdalae 



Emulsum Asafoetidse 
Emulsum Chloroformi 



Composition. 

Ammoniac 

Water, sufficient to make 

Sweet Almond 

Acacia .... 

Sugar .... 

Water, sufficient to make 

Asafetida 

Water, sufficient to make 

Chloroform . 

Expressed Oil of Almond 

Tragacanth . 

Water, sufficient to make 



4 Gin. 
100 Cc 
6 Gin. 
1 " 

3 " 
100 Cc. 

4Gm. 
100 Cc 

4 " 
6 " 

15 Gm. 
100 Cc. 



Special Remarks. 

Emulsion of Almond. The acacia and sugar prescribed in the 
official formula are by no means essential to the formation of a per- 
fect emulsion, although they add to the stability of the preparation. 
Emulsion of almond more closely resembles cow's milk in appear- 
ance than any other seed or oil emulsion made ; the fixed oil present 
is kept suspended in a very fine state of division, by means of the 
albuminous matter known as emulsin or synaptase, which constitutes 
the chief body of the seed. Blanched almonds should always be 
used, so that a pure white liquid may result. Almonds are best 
blanched bv macerating them in warm water until the skin becomes 
loose, when it can be quickly removed by simple pressure between 
the fingers. Emulsion of almond should always be made fresh 
when wanted. 

Emulsion of Chloroform. The official formula yields a stable 
emulsion, from which neither chloroform nor oil separates even in a 
week's time, but, since the preparation is never kept in stock, a 
smaller quantity of tragacanth will prove equally efficacious, and I 
should prefer to reduce it to two-thirds of the prescribed quautity, 
which yields a more fluid but very satisfactory emulsion. 



CHAPTER XXVII. 

MIXTURES. 

The term " mixture" in pharmacy, and more particularly in dis- 
pensing operations, is applied to liquid medicines which either con- 
tain insoluble substances in suspension or are composed of two or 
more liquids, with or without the addition of saline or other material 
in solution ; in its more restricted application the term is applied to 
such medicines as are intended for internal administration. In only a 
few cases, in which the stability of the preparation for a considerable 
length of time can be reasonably assured, are mixtures kept in stock ; 
hence the extemporaneous preparation of mixtures is a matter of 
constant occurrence, as it is a favorite method of administering medi- 
cines with physicians, because more extended use can be made of 
excipients and flavoring agents, with the view of improving the mix- 
ture pharmaceutically and therapeutically. Considerable skill and 
judgment are frequently necessary in the preparation of mixtures, so 
that the object of the prescriber may be fully attained and each frac- 
tion of the mixture contain an aliquot part of all the ingredients. 
All insoluble or only partly soluble substances, particularly those of 
a vegetable nature, should be brought to the condition of smooth and 
uniform suspension, by trituration in the form of very fine powder 
with the liquid in the mortar; this is best done by first rubbing into 
a smooth paste with a portion of the liquid and then diluting this 
with the remainder, constantly stirring. Calcined magnesia or mag- 
nesia and charcoal can best be brought into a uniform mixture with 
water, by stirring at once with sufficient water to overcome the ten- 
dency of the magnesia to u set" in a gelatinous mass; a small quantity 
of water added to calcined magnesia also causes it to become gritty 
and difficult to mix. Some prefer to «fdd the magnesia to the water 
and diffuse by agitation. In all cases the mixture should be passed 
through a loosely textured cloth. All powerful remedies, such as 
mercuric chloride, arsenous acid, the salts of morphine, strychnine, 
etc., should always be brought to a state of solution before they 
are added to the other ingredients of a mixture, so as to insure a 
uniform distribution throughout the liquid. Substances which are 
readily diffusible in the liquid by agitation of the bottle, do not, as 
a rule, require the addition of an excipient to insure their uniform 
suspension, but other insoluble substances which are relatively much 
heavier than water, or are inclined, to float on the surface of the 
liquid, demand the addition of some mucilaginous or other body to 
increase the density. Syrup, glycerin, or honey is frequently prefer- 



296 PRACTICAL PHARMACY. 

able to acacia or tragacanth, especially in the case of heavy metallic 
salts, liable to form, with the gum, a compact mass, which cannot 
be readily suspended by agitation. 

Formerly emulsions were recognized among the mixtures, but 
they are now considered as a distinct class of preparations, the char- 
acteristics of which have been described iu the preceding chapter. 

In connection with the preparation of mixtures, it becomes neces- 
sary to consider the subject of incompatibility; this term is applied 
to the antagonism or disability of harmonious coexistence, which is 
exhibited by numerous substances when brought into contact with 
certain other substances. Liquids which are not mutually inter- 
soluble, although they can be brought into homogeneous mixture 
with the aid of excipients, are often said to be incompatible with each 
other, as in the case of fixed oils and water, chloroform and glycerin, 
etc. ; but, strictly speaking, the term incompatibility in pharmacy 
refers to the relation existing between two or more bodies, by reason 
of which they cannot be mixed without undergoing or producing 
some change of a physical or chemical nature. Three kinds of in- 
compatibility exist — pharmaceutical, chemical, aud therapeutical, of 
which the pharmacist must take note, and for the proper understand- 
ing of which he must rely upon his knowledge of the physical, 
chemical, and medical properties of drugs. 

Pharmaceutical Incompatibility is such as effects the physi- 
cal properties of substances, and is chiefly confined to their solubility ; 
it may result in the partial or total separation of matter held in solu- 
tion, which may include valuable constituents of the mixture, or it may 
simply cause a separation of liquids from each other. The changes 
due to pharmaceutical incompatibility, being entirely of a physical 
character, can often be avoided or overcome by judicious manipula- 
tion or by the addition of some suitable excipieut or protective agent. 
The mixture of strongly alcoholic liquids with solutions of acacia — 
of acid or neutral aqueous liquids w T ith resinous tinctures — of alcoholic 
or ethereal solutions of volatile oils and other substances with aqueous 
liquids — the admixture of solids which undergo liquefaction by reason 
of intersolubility, as iu the case of camphor with solid fats, chloral 
hydrate, thymol, salol, menthol, etc. — the addition of certain metallic 
salts to vegetable solutions, causing gelatinization, as in the case 
of tincture of ferric chloride and mucilage of acacia — are all in- 
stances of pharmaceutical incompatibilities. In many cases of 
physical incompatibility, the trouble may be averted by appropriate 
dilution before mixing, as for instance, when spirit of nitrous ether 
or tincture of ferric chloride is to be mixed with a strong mucilage 
of acacia : a perfectly harmonious mixture, free from precipitate or 
gelatinization, can be prepared if the mucilage as well as the spirit or 
tincture be first largely diluted with water, and such should be the 
invariable rule when these substances are prescribed together. 
When tinctures of asafetida, guaiac, lupulin, myrrh, and similar 
substances are ordered in combination with aqueous saline liquids, 






MIXTURES. 297 

separation of the resinous matter will invariably result, unless a pro- 
tective agent is present, by means of which the finely divided pre- 
cipitate is kept in perfect suspension. Syrups and glycerin are 
frequently associated with resinous tinctures by physicians, for the 
purpose of avoiding the separation of resin, and, if used in sufficient 
quantity, will answer the purpose ; in the absence, however, of such 
provision, it is the duty of the pharmacist to add some inert sub- 
stance which will enable him to prepare a mixture of uniform com- 
position. If the following two prescriptions be dispensed exactly as 
ordered, the resin of the tincture in both cases would be precipitated 
and gradually deposited on the sides and bottom of the bottle, thus 
depriving the patient of an important part of the medicine ; no 
amount of shaking will even temporarily suspend the precipitated 
resin uniformly, but only increase its separation from the liquid. 

K- — Potassii Bromidi . . .^iv. R . — Potassii Chloratis . #ij. 

Tinct. Lupulini . . jfj. Tinct. Guaiaci . . %}. 

Aqua? Menthse Vir. . ^ij. — M. Aquae . . q. s. ad ^iv — M. 

By mixing the resinous tincture or fluid extract with powdered 
tragacanth in a mortar, and then adding the water or saline solution 
gradually, with constant stirring, a perfect mixture can be obtained 
from which the suspended resin separates very slowly in a finely 
divided form, so as to be readily reincorporated by simple agitation. 
The proportion of tragacanth to be used will depend, to some extent, 
upon the volume of dilution; for instance, in the above prescriptions, 
10 or 12 grains will be amply sufficient, whilst if a 6 oz mixture were 
intended 15 or 18 grains would be preferable. As a rule, 10 grains 
of tragacanth will be required for each flnidounce of a tincture or 
half fluidounce of a fluid extract. 

The turbidity caused by the partial separation of volatile oil or 
other bodies when an alcoholic solution of the same is added to 
aqueous fluids, is due to the decreased solubility of the substance in 
the diluted spirit and cannot be overcome by the ordinary methods ; 
filtration with the aid of such media as purified talcum, calcium 
phosphate, etc., is not always permissible, and then the application of 
the general rule — never to dispense a mixture containing insoluble matter 
without a " Shake well before using " label — is all that can be done by 
the pharmacist. 

Chemical Incompatibility, as its name indicates, depends upon 
the chemical properties of substances, and invariably involves decom- 
position of one or all of the bodies brought into contact, with the 
resulting formatiou of new compounds. The existence of chemical 
incompatibility has proven most valuable in the study of inorganic 
and organic matter, and forms the basis upon which rests the very 
extensive superstructure of analytical chemistry. Chemical decom- 
position is not always accompanied v by the separation of insoluble 
matter, for, in numerous cases, the newly formed compound is per- 
fectly soluble in the liquid present. Among the most dangerous 



298 PRACTICAL PHARMACY, 

ineornpatibles are mixtures of the chlorates or permanganates with 
readily oxidizable substances, hence particular care must be exercised 
in bringing the former into intimate contact with organic matter, so as 
to avoid possible serious explosions. 

There are different conditions under which chemical incompati- 
bility manifests itself, chief among which are the following : 

1. Two salts composed of different acid and basic radicals, when 
brought together in a state of solution, mutually decompose each 
other; the resulting new compounds may both remain in solution, 
in which case no evidence of decomposition is apparent and it scarcely 
seems proper to consider the two salts used as incompatible with each 
other, as when solutions of ammonium chloride and potassium iodide 
are mixed, or those of cupric sulphate and zinc acetate. When, 
however, one of the new compounds is insoluble in the liquid and is 
deposited as a precipitate, true incompatibility has been established ; 
as in the case of a mixture of solutions of lead nitrate and potassium 
iodide, lead iodide being precipitated. Sometimes the new insoluble 
compound enters into union and solution w T ith one of the original 
substances, if the latter is present in excess, in which case the 
chemical incompatibility of the original two substances remains, and 
the resolution of the insoluble compound must be looked upon as a 
new operation. Such examples are presented by mercuric chloride 
and potassium iodide, if either salt is in excess, or by potassium 
cyanide and silver nitrate, the former salt being in excess. 

2. Salts of the heavy metals, and, in many instances, also those of 
the alkaline earths and earths, are decomposed by the alkalies or 
their carbonates, forming insoluble compounds, hence incompatibility 
exists between such salts. As examples may be mentioned mercuric 
chloride with potassium hydroxide, lime-water with sodium bicarbo 
nate, calcium chloride with potassium carbonate and alum with sodium 
carbonate. 

Bismuth subnitrate is frequently prescribed in a mixture with 
sodium bicarbonate, and almost invariably decomposition takes place, 
resulting in a more or less violent disengagement of carbon dioxide ; 
as the reaction takes place slowly, at times it may not occur until the 
mixture has been transferred to a bottle and corked. The remedy 
lies either in using the bismuth subcarbonate in place of the subni- 
trate, or in mixing the subnitrate and bicarbonate in a mortar and 
adding a little boiling water, so as to hasten and complete the 
reaction. 

3. When oxidizing agents are brought into direct contact with 
organic matter, chemical reaction at once ensues, which is often of a 
violent nature, and is among the most important incompatibilities 
met with. To this class belongs the trituration of potassium chlorate 
with sulphur, sugar, tannin, or acacia ; the solution of chromic acid 
or potassium permanganate with glycerin, etc. 

4. The association of the salts of gold and silver with reducing 
agents gives rise to an exhibition of incompatibility, by converting 






MIXTURES. 299 

the gold and silver to the metallic state, thereby rendering them less 
soluble. All organic matter has a decomposing effect upon the com- 
pounds of gold and silver, but more particularly glucose, honey, 
syrup, and glycerin; heuce these should be avoided in prescriptions. 

5. Salts when brought in contact, either in the dry state or in solu- 
tion, with acids or bases stronger than their own acid or basic radi- 
cals, will suffer decomposition, the result being new compouuds with 
the evolutiou of the old acid or base. If the liberated acid or base be 
volatile, it will be given off in gaseous form, and may cause serious 
annoyance to the dispeuser unless proper precautions be observed. 
The preparation of the official solution of ammonium acetate proves 
the incompatibility of all carbonates with acids, and the development 
of ammoniacal vapors when ammonium salts are triturated with 
potassa proves the incompatibility of salts with stronger bases. 

Whenever carbonates are prescribed with an acid liquid, the dis- 
penser should allow the reaction to be completed before corking 
the vial, so that the greater portion of the gas may escape, and 
caution the patient to keep the vial in a cool place and not violently 
agitate it. If a viscid or saponaceous liquid is also to be added, 
as mucilage or syrup of senega, it is all the more important that 
chemical reaction be allowed to subside before the addition is made, 
and that as little carbon dioxide as possible be kept in the solution. 

With some physicians, the following is a favorite prescription : 

H- — Ammonii Carbonatis \ -. 

Ammonii Chloridi J 3J* 

Syrupi Scillee \ ~ ~. 

Syrupi Senegre J * ' * " • oJ- 

Syrupi Tolutani §ij. 

Ft, sol. 

The proper way of mixing these ingredients is to rub the salts to 
a fine powder, and add to them, while in the mortar, the syrups of 
squill and tolu previously mixed, stirring the mixture with the pestle 
until effervescence ceases; finally add the syrup of senega. If a per- 
sistent froth forms on the surface of the liquid, this may be quickly 
dispelled by carefully sprinkling a few drops of alcohol over it, before 
the mixture is transferred to a bottle. 

To this class of incompatibilities belongs also the decomposition 
and precipitation caused in fluid extract of liquorice by acids; the 
sweet principle in liquorice is ammonium glycyrrhizate, which, upon 
addition of dilute sulphuric or other acid, is decomposed, the glycyr- 
rhizin being deposited on the sides and bottom of the vessel. Phy- 
sicians sometimes prescribe an acid solution of quinine, together with 
fluid extract of liquorice, in the hope of disguising the bitter taste, 
overlooking the fact that the bitter taste of quinine is always intensi- 
fied by bringing the latter into solution. As the intended effect of 
the liquorice is defeated by the presenpe of an acid, there is but one 
course open to the pharmacist with prescriptions of this kind, namely, 
to omit the acid, triturate the quinine with the fluid extract or syrup 



300 PRACTICAL PHARMACY. 

of liquorice, and dispense the mixture with a " Shake well before 
using " label. It is advisable, at the same time, to explain to the 
physician what has been done, giving the reason therefor, so as to 
avoid, if possible, a repetition of the blunder. 

The decomposition of salts by stronger acids or bases is frequently 
resorted to intentionally, as in the well-known " Neutral Mixture," 
made from lemon juice and potassium bicarbonate, aud in " Preston 
or Smelling Salts," composed of ammonium chloride and lime, usually 
flavored with oil of lemon and oil of lavender. 

6. The salts of the alkaloids are decomposed by certain salts of 
the alkalies, with the production of insoluble or sparingly soluble 
compounds, therefore such combinations require the special attention of 
pharmacists in order to guard against accidents. As a rule, the alkali 
carbonates, iodides, aud bromides are incompatible with alkaloidal 
salts, while the sulphates, nitrates and chlorides appear to cause no 
trouble ; hence in the case of the first-named salts the directions to 
shake the mixture should always be put on the bottle. In a few 
rare cases, when a sufficient quantity of solvent is present to take up 
the alkaloid in its pure state, it may be preferable to use the latter in 
place of its salt, as, for instance, in the following prescription : 

R. — Codeinse Sulphatis gr. viij. 

Potassii Bromidi 5j. 

Aquae destillatae q. s. ut ft. % iv. 

Ft. sol. 

It was found that if the codeine sulphate was used, as prescribed, 
a precipitate invariably formed, which was with difficulty uniformly 
suspended by agitation, but by using the pure alkaloid codeine in place 
of the salt, a permanently clear solution was obtained. Morphine 
sulphate is sometimes prescribed in conjunction with sodium bicar- 
bouate, the result being a minutely crystalline precipitate. Quinine 
sulphate and potassium acetate should not be associated in solution, 
on account of the slight solubility of the quinine acetate, which is 
formed as a very bulky precipitate aud may cause solidification of 
the mixture. 

7. Vegetable astringents are incompatible with alkaloids, gluco- 
sides, albumen, gelatin, and many metallic salts ; in some cases, curdy 
precipitates are formed, which afterward adhere to the sides of the 
vessels, while in other cases light, readily diffusible precipitates are 
obtained, or possibly only turbidity or discoloration ensues. The 
character of such a mixture depends, to some extent, upon the degree 
of dilution and the presence of other bodies. Quinine and tannin 
are sometimes prescribed together, but should never be triturated 
with water, as a tough insoluble mass would at once be formed ; the 
two substances are best mixed with syrup and afterward diluted with 
water, if desired, when the insoluble quinine tannate can be readily 
suspended by simple agitation. The formation of ink depends upon 
the incompatibility of tannin with iron salts, and is a fruitful source 



MIXTURES. 301 

of annoyance to the pharmacist. The value of strong coffee and tea 
or similar astringent infusions as antidotes for metallic poisoning, is 
due to the formation of sparingly soluble compounds. Vegetable 
astringents have been found incompatible also with spirit of nitrous 
ether, several explosions having occurred from mixing the latter 
with the fluid extracts of uva ursi, matico, geranium, and even 
gentian ; the gas liberated by these reactions appeared heavily 
charged with some nitrous compound. 

The presence of certain protective agents has been known to avert, 
or at least to modify, the chemical decomposition between some 
substances ; in such cases it is, of course, essential that the protective 
agent be mixed with one of the substauces before the other is added. 
The following examples will show the action of glycerin, acacia, and 
syrup, in this respect. Physicians frequently prescribe cocaine 
hydrochloride or morphine salts in solution, together with borax, 
which causes precipitation and thus unfits the solution for use; the 
addition of a little glycerin prevents the decomposition. Zinc chloride 
and borax, prescribed together in solution, will cause the formation 
of insoluble zinc borate, which is prevented, however, by the pres- 
ence of glycerin ; strange to say, such a clear solution containing 
glycerin will bear further dilution with water only up to a certain 
point, beyond w T hich precipitation ensues. The exact action of the 
glycerin in the foregoing cases is not clearly understood, but, reason- 
ing from the effect of glycerin on borax alone, it may be assumed 
that a similar action obtains in the mixture with alkaloidal and other 
salts, the glycerin decomposing the borax, by liberating a part of the 
boric acid, which itself is perfectly compatible with the salts above 
mentioned, as has been shown by making the solutions w 7 ith boric 
acid instead of borax or borax and glycerin. On the other hand, 
glycerin may sometimes act as a disturbing agent and cause decom- 
position which otherwise would not occur. Borax and sodium 
bicarbonate are perfectly compatible in aqueous solution, and are 
frequently prescribed together ; if glycerin be present, reaction is set 
up by the boric acid liberated from the borax, and the sodium bicar- 
bonate is decomposed with copious evolution of carbon dioxide. Such 
a mixture must be made in a mortar and the reaction allowed to 
subside before bottling it. - 

Corrosive mercuric chloride and lime-water are known to be in- 
compatible, but are often ordered together with the view of utilizing 
the freshly-formed yellow mercuric oxide in moist condition ; mer- 
curic chloride will also precipitate acacia from a strong solution, but, 
if a dilute solution of mercuric chloride be added to mucilage of 
acacia and subsequently mixed with lime-water, no precipitate what- 
ever will occur for several days, when finally a grayish deposit of finely 
divided metallic mercury or mercurous oxide is formed. When a 
physician orders such a combination as mercuric chloride, water, 
mucilage of acacia, and lime-water, the object is plainly to keep the 
mercuric oxide better suspended, and the mixture should be made by 



302 PRACTICAL PHARMACY. 

adding the mucilage last of all, after decomposition of the mercuric 
chloride has been completed. 

Chemical incompatibility may result in rendering a mixture less 
active or even inert from the formation of insoluble compounds, as 
when tartar emetic is ordered in combination with syrup of wild 
cherry or tincture of digitalis with tincture of cinnamon, etc.; on the 
other hand, the medicinal activity of the mixture may be intensified 
by the formation of poisonous compounds, as in the case of mer- 
curous iodide with soluble iodides, producing mercuric iodide and 
metallic mercury, or the association of calomel with soluble chlorides 
or iodides, etc. In all such cases the pharmacist should consult the 
prescriber and acquaint him with the prospective results. 

It must not be supposed, however, that because precipitation occurs 
as a result of chemical incompatibility, the mixture is always ren- 
dered inert thereby ; the decomposition is often inteutional with a 
view to obtaining the insoluble compound in a freshly formed and 
more active condition. Such instances are found in the well-known 
" black wash " and "yellow wash" (prepared from lime-water with 
calomel and corrosive sublimate respectively), in the mixture of solu- 
tions of tannin and of lead subacetate, which produce a magma-like 
precipitate of lead tannate, and in the frequently prescribed mixture 
of zinc sulphate with a solution of lead acetate, giving the freshly 
precipitated lead sulphate, which is much preferred. The official 
compound iron mixture is another instance of intentional decomposi- 
tion, the newly formed ferrous carbonate being the object sought. It 
requires no little judgment on the part of the pharmacist to discern 
when the prescriber intentionally orders chemically incompatible 
substances together, or when this happens from a want of familiarity 
with chemical reactions. 

Therapeutical Incompatibility depends entirely upon the 
antagonism existing between drugs in regard to their physiological 
effect or medical action, and does not properly 
fig. 206. belong to the domain of pharmacy ; the remedy 

for such a condition lies solely in the hands of 
the physician, who is supposed to be familiar with 
the requirements of his patients and the thera- 
peutical action of drugs. Sometimes the intended 
medicinal effect of a substance is destroyed by 
chemical action, as when ammonium carbonate is 
associated with syrup of squill ; this, however, 
cannot be considered as a therapeutical incom- 
patibility. 

While it is well understood in prescription 
practice that solutions should always be filtered 
through a pledget of cotton placed in the throat 
of a funnel to remove motes and specks, the rule 
should also prevail, in dispensing mixtures, that the mixture be 
strained through bolting-cloth, in order that the insoluble matter be 




MIXTURES. 



303 



free from lamps and in a uniformly divided state; the straining is 
best accomplished by placing the bolting-cloth between the upper 
and lower part of a rubber or tin funnel, as shown in Fig. 206, 
which can be inserted directly into the prescription vial. 

The subject of incompatibility is practically an endless one, but 
the following summary will, to some extent, aid the dispenser in 
determining the character of numerous mixtures ; it must be borne 
in mind, however, as stated before, that not all incompatibles produce 
inert or poisonous compounds, and that while in many cases the 
incompatibility can be overcome by appropriate means, physicians 
frequently associate incompatible substances for a specific purpose. 



Summary of Incompatibilities. (After Hager 



Acacia 

Acids in general 

Acid, Arsenous 
Acid, Carbolic 

Acid, Chromic 

Acid, Picric 

Acid. Salicylic 



Acid, Tannic 

Albumen 
Alkaloidal Salts 



Alum 

Ammonium Acetate | 

Ammonium Bromide j 

Ammonium Chloride 
Ammonium Phosphate 
Amyl Nitrite 



Antimony, Sulphurated 
Antipyrine 

Apomorphine Hydrochloride 



with ferric chloride, alcohol, borax, lead salts, and 
ethereal tinctures. 

" alkalies, alkaline fluids, acetates, and metallic 
oxides. 

" lime-water, magnesia, and oxides of iron. 

" potassium permanganate, iodine, bromine, caus- 
tic alkalies, and iron salts. 

" glycerin, alcohol, ether, essential oils, and or- 
ganic matter in general. 

" alkaloidal salts, dry acids, iodine, sulphur, and 
organic salts. ( These incompatibilities extend 
also to the salts of picric acid ) 

" potassium permanganate, iron salts, lime-water, 
potassium iodide, and soap. (These incom- 
patibilities extend also to the salts of sali- 
cylic acid ) Alkali salicylates will darken 
unless an excess of acid be present. 

" mucilages, tartar emetic, silyer nitrate, metallic 
salts in general, alkaloids and their salts, lime 
water, potassium chlorate, alkali carbonates 
and bicarbonates, albumen, gelatin, and 
chlorine water. 

" mineral acids, alcohol, mercuric chloride, and 
vegetable astringents. 

" borax, tannin, and all vegetable astringents, 
alkali carbonates, the permanganates, iodides, 
liquorice, strong mucilages, magnesium car- 
bonate, and alkaline tinctures. 

" alkalies and alkali carbonates. 

" mineral acids, alkali carbonates, chlorine, potas- 
sium chlorate and dichromate, silyer nitrate, 
mercurous chloride and nitrate 

" carbonates of the alkalies and earths. 

" alcohol, tinctures in general, alkali carbonates, 
calomel, lead salts, potassium iodide, the 
bromides and ferrous salts 

" sodium bicarbonate, potassium bitartrate, bis- 
muth subnitrate, and calomel. 

" sodium salicylate (dry), calomel, chloral hy- 
drate, spirit of nitrous ether, and nitrites in 
general. 

" sodium carbonate and bicarbonate, iodine, tan- 
nin, and iron salts. 



304 



PRACTICAL PHARMACY 



Barium Chloride with 

Bismuth Subnitrate " 

Calcium Chloride 
Calcium Hypophosphite 

Calomel (Mercurous Chloride) " 



Chloral Hydrate 



Chlorine Water 



Corrosive Sublimate (Mercuric " 
Chloride) 

Digitalis " 

Iodine 



Iodoform 



Iron, Keduced 
Iron Salts 



Lead Acetate (also Lead Sub- 
acetate) 



Lime, Chlorinated 
Lime-water 
Morphine Salts 



sulphuric and phosphoric acids and their salts, 
carbonates, tartrates, vegetable infusions, and 
medicinal wines. 

calomel, tannin, sulphur/^and antimony sul- 
phide. 

calomel, sulphates, phosphates, tartrates, and 
carbonates. 

potassium chlorate, iodide, and permanganate ; 
also chlorinated lime. ( These incompatibili- 
ties extend to all hypophosphites.) 

acids, acid salts, alkali carbonates, lime water, 
ammonium chloride, iodine, potassium iodide, 
ferrous chloride and iodide, sulphur, bitter- 
almond water, cherry-laurel water, antimony 
sulphide, and antipyrine. 

water (slow decomposition), warm water, alkali 
carbonates and organic salts, calomel, potas- 
sium cyanide, antipyrine, salts of ammonium, 
mercurous nitrate, permanganates, alcohol, 
tinctures in general, bromides, and iodides. 

alkalies and their carbonates, ammonium salts, 
salts of the organic acids, lead salts, silver 
nitrate, mucilages, tannin, extracts, tinctures, 
infusions, emulsions, and milk. 

lime-water, soap, iodine, opium, potassium 
iodide, organic acids, tannin, and alkali car- 
bonates. 

tannin, lead acetate, iodine, potassium iodide, 
iron salts, and alkali carbonates. 

ammonia, starch, metallic salts, fatty and vola- 
tile oils, emulsions, carbolic acid, chloral 
hydrate, acacia, tragacanth, magnesium, car- 
bonates, and sodium thiosulphate (hyposul- 
phites.) 

silver and other nitrates, potassium chlorate, 
nitrites, and mineral acids. (The modifica- 
tion or destruction of the odor of iodoform 
by the following substances points to incom- 
patibility: tannin, Peru balsam, tincture of 
myrrh, naphtalene, cumarin, and the volatile 
oils of anise, bergamot, fennel, peppermint, 
and turpentine.) 

aloes, tannin, infusions, extracts, metallic and 
alkaloidal salts. 

alkali carbonates and bicarbonates, mucilages, 
tannin, infusions, extracts, and astringent 
tinctures. 

opium, lime-water, ammonium chloride, alum, 
potassium iodide, iodine, acacia, tragacanth, 
tannin, carbonates and sulphates, .and sul- 
phuric and hydrochloric acids. (Normal 
lead acetate is compatible with mucilage of 
acacia, but the basic or subacetate causes pre- 
cipitates, even in minute quantities.) 

ammonium chloride, sulphur, tannin, metallic 
sulphides, glycerin, volatile oils, and fatty 
substances. 

acids, ammonium salts, carbonates, tartrates, 
metallic salts, tannin, infusions, and many 
tinctures. 

the salts of iron, manganese, and silver, potas- 
sium chlorate and permanganate, nitrites and 
nitrates, carbonates of the alkalies and the 
earths, amyl nitrite and bitter-almond water. 



MIXTURES. 



305 



Musk 

Opium, including the Tincture 
and Extract of Opium 

Pepsin 

Potassium Bromide 

Potassium Chlorate 



Potassium Iodide 
Potassium Permanganate 

Silver Xitrate 

Sodium Bicarbonate 
Tartar Emetic 



with acids, acetates, tannin, ergot, and metallic salts. 

" alkali carbonates, tannin, metallic salts, iodine, 
chlorine water, and the preparations of nux 
vomica and belladonna 

" alkaline substances, alcohol, and tinctures in 
general. 

" mineral acids, chlorine water, and the salts of 
mercury and silver. 

" mineral acids, tannin, catechu, sulphur, char- 
coal, calomel, sulphites, ferrous salts, nitrites, 
hypophosphites, sugar, honey, and vegetable 
powders. 

" acids and acid salts, alkaloidal salts, silver 
nitrate, ferric salts, potassium chlorate, spirit 
of nitrous ether, and salts of lead and mercury. 

" fatty and volatile oils, alcohol, glycerin, am- 
monia and ammonium salts, alkaloids, sul- 
phur, charcoal, and organic substances in 
general. 

" hydrochloric, sulphuric, acetic, and tartaric 
acids and their salts, hydrocyanic acid, iodine, 
potassium iodide and bromide, antimony, sul- 
phide, sulphur, tannin, alkali carbonates, car- 
bonates of the earths, and astringent tinctures. 

" acids and acid salts, tannin, metallic and alka- 
loidal salts. 

" acids and alkalies, calomel, tannin, soap, acacia, 
opium, and vegetable astringents. 



In Europe, effervescing mixtures are often prescribed under the 
name " Saturations," which are made by adding to lemon-juice, 
vinegar, tartaric or citric acid solution, sufficient of an alkali car- 
bonate to produce a neutral or nearly neutral salt, the liquid retain- 
ing in solution a large portion of the carbon dioxide evolved, which 
adds materially to the refreshing taste of the mixture. In the Phar- 
macopoeia will be found a complete table of the quantity of different 
alkalies and alkali carbonates necessary to neutralize 100 parts of 
the various official acids. 

The Official Mixtures. 

Of the four preparations recognized as mixtures in the present 
Pharmacopoeia, only two are fit to be kept on hand for several days 
or longer, in warm weather ; the other two should be freshly made 
when needed, owing to their rapid deterioration. 



Name. 



Mistura Cretae 



Table of the Official Mixtures. 

Composition. 
Compound Chalk Powder 
Cinnamon Water 

ater, sufficient to make 



Mistura Ferri Composita 



f Co 
\ GL 
I W 



f Ferrous Sulphate, cryst. 
| Myrrh . '. 

J Sugar. 

I Potassium Carbonate . 
J Spirit of Lavender 
t Kose Water, sufficient to make 
20 



200 Gm. 
400 Cc. 
1000 " 
6Gm. 
18 " 
18 " 
8 " 
60 Cc. 
1000 " 



306 



PRACTICAL PHARMACY . 



Name. 



Mistura Glycyrrhizse Composita 



Mistura Ehei et Sodse 



Composition. 
f Pure Extract of Glycyrrliiza 

Syrup 

I Mucilage of Acacia 
-{ Camphorated Tincture of Opium 

AVine of Antimony 
I Spirit of Nitrous Ether 
{ Water, sufficient to make 
f Sodium Bicarbonate 
| Fluid Extract of Rhubarb 
I Fluid Extract of Ipecac 
j Glycerin .... 
i Spirit of Peppermint . 
[_ Water, sufficient to make 



30 Gm 


50 Cc. 


100 " 


i 120 " 


60 " 


30 " 


. 1000 " 


35 Gm 


15 Cc. 


3 " 


. 350 " 


35 " 


. 1000 " 



Special Remarks. 

Mistura Cretce. The compound chalk powder directed for this 
preparation is the official powder composed of 3 parts of prepared 
chalk, 2 parts of acacia, and 5 parts of sugar, the insoluble chalk 
being kept in suspension by the gum and sugar in solution. Preci- 
pitated calcium carbonate must not be used in making this mixture, 
as it is crystalline and does not make so smooth a preparation, nor 
remain so perfectly in suspension as the prepared chalk. Chalk 
mixture should be made in small quantities and kept in a cold place. 

Mistura Ferri Composita. The preparation of this mixture presents 
no difficulty if good tears of myrrh be selected and the directions 
strictly followed. The reaction between the iron and potassium 
salts, resulting in the formation of ferrous carbonate and potassium 
sulphate, takes place in the myrrh emulsion, by which the insoluble 
ferrous carbonate is kept in suspension fairly well. Unless in full 
and well -corked bottles, the mixture, at first of a dirty-greenish 
color, is hardly protected against oxidation by the small quantity of 
sugar present, therefore should be freshly made when needed. 
Compound iron mixture is also known as Griffith's mixture, and 
is sometimes prescribed under that name. 

Mistura Glycyrrhizw Composita. The present official formula differs 
from that of 1880, in ordering syrup and mucilage in place of sugar 
and powdered acacia, whereby the preparation of the mixture is ex- 
pedited. The finished product is rather unsightly and by no means 
in keeping with modern elegant pharmacy. The formula suggested 
by Charles Tilyard, in 1860, yields an equally efficient and far 
handsomer preparation ; it prescribes a larger proportion of sugar 
(by no means a disadvantage), and can be still further improved by 
the use of purified extract of liquorice, as now ordered by the 
Pharmacopoeia. The formula, as modified and adapted to the propor- 
tions of the Pharmacopoeia, is as follows : Dissolve 30 Gm. of purified 
extract of glycyrrliiza in 300 Cc. of water; add 120 Cc. of cam- 
phorated tincture of opium, 60 Cc. of antimonial wine, and 30 Cc. 
of spirit of nitrous ether, and set the mixture aside for twelve or 
twenty-four hours, with occasional agitation ; filter the liquid into 



MIXTURES. 307 

a bottle containing 100 Cc. of mucilage of acacia and 600 Gin. of 
granulated sugar, and wash the filter with sufficient water to bring 
the volume of the finished product up to 1000 Cc. The sugar is 
readily dissolved by agitatiou, the result being a thin, rich-looking 
clear syrup which keeps admirably. This preparation is popularly 
known as " Brown Mixture." 

Mistura Rhei et Sodce. Ordinarily, when fluid extract of rhubarb 
is mixed with water, copious precipitation of resinous aud extractive 
matter at once ensues, but this is prevented, in the official mixture, 
by the alkali bicarbonate, and the solution is preserved by the 
glycerin subsequently added. It keeps quite well, but is not often 
prescribed. 



CHAPTEE XXVIII. 

PILLS. 

Pills are a very convenient mode of administering medicines, the 
chief advantage lying in the small bulk to which the medicine is 
reduced and the almost complete disguise of bitter and nauseous 
remedies, by reason of their being swallowed without previous masti- 
cation. Pills are admirably adapted for the administration of heavy 
metallic substances not readily suspended in liquids, and also in cases 
in which the action of the medicine is to be slow, or even retarded until 
it reaches the lower bowels. The usual shape given to pills is that 
of a sphere or globe, although an ovoid shape is also sometimes 
used, and, in a few cases, even the lenticular shape is preferred. 
Their weight ranges from less than 0.06 Gm. to 0.3 Gm. (1 gr. to 5 gr.) 
for vegetable substances, or about 0.5 or 0.6 Gm. (8 to 10 grains) 
for heavy mineral compounds ; if a pill exceeds this weight it is 
called a bolus. Boluses are occasionally made weighing 1.3 or 2.0 
Gm. (20 or 30 grains) each and are often of a softer consistence 
than pills. Very small pills coated with sugar, are called granules. 

Although of late years the extemporaneous preparation of pills has 
materially decreased, and in some localities has almost entirely disap- 
peared, the operation must yet be considered one of the most impor- 
tant pharmaceutical manipulations, and is deserving of a lengthy dis- 
cussion, because the opportunities for a practical acquaintance with 
the details of the work are growing less day by day, owing to the 
untiring efforts of manufacturers to induce physicians to specify 
factory-made pills on their prescriptions. 

The most important step in the preparation of pills is the forma- 
tion of a proper mass, which should consist of a paste, sufficiently 
plastic to admit of being moulded without adhering to the moulds, 
yet firm enough to prevent the pills from losing their original 
shape. Although a firm consistence should characterize every well- 
made pill mass, its ready disintegration and solution in the fluids of 
the stomach and bowels, are of paramount importance, and it is essen- 
tial to so unite the ingredients of a pi 11 -mass that ready separation 
in the stomach may be assured. Plasticity is that peculiar condition 
in which adhesiveness and firmness are properly balanced ; the former 
of these properties is due to a partial softness, which enables the 
particles of the mass to adhere to each other, thus imparting tenacity 
to the whole. Some substances possess this adhesiveness in them- 
selves, but require the addition of a liquid — water or alcohol — in 
order to develop it; as, for instance, gums and resinous drugs. Other 



PILLS. 



309 



substances possess do inherent adhesive properties, and, in such cases, 
it becomes necessary to impart tenacity to them, by the addition of 
some adhesive liquid or solid material ; such substances are camphor, 
calomel, bismuth salts, some saline or vegetable powders, reduced 
iron and the like. Firmness in a pill-mass is as essential as adhe- 
siveness, and, while the latter is brought about by a state of partial 
solution or fluidity, so, inversely, the insolubility of some particles 
is necessary for the required firmness. The substances added to pill- 
masses as adhesive or absorbent agents are known as excipients, and 
must be employed judiciously, so that the constituents of the mass 
be not modified in their action nor the bulk unnecessarily increased. 
After each addition, the mass should be well kneaded, which, itself 
having a softening influence, by reason of the heat generated, enables 
the operator to judge of the true condition of the mixture. When- 
ever possible, all constituents of a pill-mass should be reduced to 
very fine powder, before the addition of any excipient, as only in 
this condition can the homogeneity of the mass as well as the sub- 
sequent accurate division of doses be assured. Small quantities of 
potent remedies, such as alkaloids, narcotic extracts, toxic chemi- 
cals, etc., are preferably triturated with a little sugar of milk, before 
mixing them with the other ingredients, to facilitate uniform dis- 
tribution. 



Fig. 207. 



Fig. 208. 





Sectional view of properly-shaped pill mortars. 



Whenever substances are ordered in a pill-mass, in quantities which 
it is impossible or inconvenient to weigh accurately, as for instance, 
aconitine 0.001 Gm., digitalin 0.003 Gm., veratrine -^ grain, strych- 
nine yL grain, etc., a dilution of the substance should be made with 
sugar of milk, in such proportions that a conveniently weighable 
quantity shall contain the desired amount of the active ingredient. 
Thus, if 0.001 Gm. of auy substance is wanted, carefully triturate 
0.010 Gm. of the substance with 0^090 Gm. of sugar of milk (or 
0.050 with 0.450 Gm. if more convenient); each 0.010 Gm. of the 
mixture will then contain -fa of 0.010, or 0.001 Gm. of the medicinal 



310 



PRACTICAL PHARMACY. 



agent. If -^ of a grain of any substance is needed, triturate J grain 
of it with 5 J grains of sugar of milk (or 1 grain with 11 grains), 
and each grain of the mixture will contain -^ grain, 2 grains will 
contain -J- grain, or 1J grains will contain J grain of the active 
ingredient. In like manner any other fractional part of a centi- 
gramme or a grain may be readily obtained. 

Pill-masses should always be made, according to the nature of the 
mass, either in iron or Wedgewood mortars, of the shape shown in 
Figs. 207 aud 208, and the mixture should be frequently scraped 
down with a stiff spatula so as to bring all particles repeatedly 
together under the pestle. Trituration by means of a pestle is essen- 
tial to produce a uniform mixture of the ingredients, and moreover 
it will be found that a mass can be formed in less time, with less 
excipient and less labor, in a mortar than on a pill-tile ; very simple 
combinations, such as blue mass and extract of colocynth, etc., may 
be effected on the pill-tile, but, for all substances requiring uniform 
blending of fine powders, and similar cases, the use of the tile is to 
be condemned. Unfortunately the misuse of the pill-tile is a 
characteristic of many American pharmacists. One rule should be 
strictly observed in making every pill-mass, namely : Never use 



Fig. 209. 



Fig. 210. 





Hand machine for mixing pill- 
masses 

the spatula with which the 
mass is scraped down for 
taking excipient from its 
container. 

Large quantities of pill- 
masses which cannot be 
conveniently handled in 
the mortar are best made 
in a special apparatus 
known as a pill-mixer, 
operated either by hand 
or steam-power. As a rule, these kneading machines consist of smooth 
iron rollers (for white pill-masses hard-wood rollers are generally 



Power machine for mixing pill-masses. 



PILLS. 311 

used), which revolve iu opposite directions, some being so constructed 
that they can be heated, if necessary, by passing steam through 
them. The ingredients for the mass are first roughly mixed in a 
basin or tank and then repeatedly passed between the rollers until 
a uniform mixture been been produced. In Figs. 209 and 210 are 
shown two sizes of iron mixers for pill-masses, made by J. H. Day 
& Co., of Cincinnati, the smaller one having a capacity of three 
pounds and the larger of thirty pounds. The tanks are porcelain 
lined, and the corrugated rollers or mixers are galvanized. As shown 
in the illustrations, the machines are easily opened and taken apart 
for cleaning purposes. While mixing a mass the rollers turn toward 
each other, and while emptying, from each other. The finished mass 
can be easily removed by tilting the machine &nd at the same time 
causing the rollers to revolve slowly in a reverse direction. 

Excipients. It being impossible to select one single substance 
as an excipient suitable for all pill-masses, owing to the variable 
properties of drugs and the many diiferent combinations ordered by 
physicians, it is essential that the pharmacist be familiar with the 
peculiarities of each excipient, in order to use the same intelligently 
and advantageously. Excipients for pill-masses may be divided into 
three distinct classes, as follows: 

1. Those which are intended to develop adhesiveness, and hence 
act as solvents. To this class belong water, alcohol, diluted alcohol, 
glycerin, and a mixture of glycerin and water. 

2. Those which are intended to impart adhesiveness ; these may 
be fluid, semi-fluid, or solid. To this class belong syrup, glucose, 
honey, mucilage and syrup of acacia, mucilage of tragacanth, 
glycerite of starch, acacia with glucose or honey, tragacanth with 
glycerin, soap with water or diluted alcohol, extract of malt, confec- 
tion of rose, manna and powdered elm bark mixed with tragacanth ; 
the last named requires the addition of syrup or glycerin and water. 

8. Those which are intended to act simply as absorbents of excesr 
sive moisture and, in a few cases, impart adhesiveness to the mass 
at the same time. To this class belong powdered liquorice root, 
soap and liquorice root, calcium phosphate, powdered orris root, 
powdered tragacanth, powdered elm bark, starch and powdered 
marshmallow. 

The first class, solvents, are employed in many cases in which physi- 
cians have ordered vegetable powders in connection with soap or 
solid extracts, the latter in insufficient quantity to form a good 
mass. Solvents must be added to pill-masses with great care, espe- 
cially when water or glycerin is used with soap or extracts ; by add- 
ing the fluid in drops and working the mass well after each addition, 
the required consistence will soon be developed, and a firm, yet plastic 
mass, be obtained, while an excess of moisture causes a softening of 
the mass, which frequently increases, and prevents the formation of 
perfect pills, besides requiring the addition of absorbent powders, 
which add to the bulk of the mass. 



312 PRACTICAL PHARMACY. 

The second class, adhesive excipients, are more extensively used than 
any other, because the majority of substances prescribed in pill form 
do not possess inherent adhesive properties, or at least insufficiently, 
for properly massing the. ingredients. Mucilage and syrup of acacia 
are the least desirable of the class, unless the pills are for immediate 
use, as pills made with acacia are apt in time to become very hard ; 
the addition of glycerin, however, obviates the difficulty. Syrup or 
glucose is usually preferred to water for massing vegetable powders, 
in the absence of soap or solid extracts. Tragacanth with glycerin 
can be most conveniently used in the form of a jelly, made by tritu- 
rating 85 grains of powdered tragacanth with 6 fluidrachrns of 
glycerin and 1 fluidrachm of water; it is an excellent excipient for 
the salts of quinine, salol, acetanilid, sodium salicylate, iodoform, 
calcium sulphide and also gallic and tannic acids, but for cinchoni- 
dine sulphate, or salicylate, acacia with glucose or honey is preferable. 
Soap with water or diluted alcohol, is the best excipient for aloes, rhu- 
barb and the various gum-resins; it cannot, however, be used with 
soluble metallic salts as those of iron, lead, copper, etc., owing to the 
formation, by mutual decomposition, of metallic oleates, which cause 
the mass to crumble. 

The necessary precaution regarding the use of water in conjunction 
with soap has already been mentioned in the preceding paragraph. 
Manna is very desirable for massing reduced iron or manganese 
dioxide, when these are prescribed alone. Extract of malt is very 
similar to glucose in its applicability, but can only be used for dark- 
colored masses. Confection of rose, at one time much esteemed as an 
excipient for mixtures of vegetable powder and metallic salts, has now 
almost gone out of use. For the valerianates of iron, quinine, or 
zinc, no better excipient can be used than acacia and alcohol in the 
following proportions : Iron, quinine, or zinc valerianate, 30 grs. ; 
powdered acacia, 10 grs. ; alcohol, 5 minims. Camphor and mono- 
bromated camphor can be made into very satisfactory pill-masses, by 
the addition of soap and oil of sweet almond or castor oil ; about 1 
grain of soap and 2 drops of oil will be sufficient for 12 grains of 
camphor. 

As an excellent adhesive agent for heavy metallic salts, such as 
bismuth subnitrate or calomel, as well as for the scale salts of iron 
and troublesome combinations like capsicum, camphor and lead ace- 
tate, Mattison's excipient powder will be found very serviceable ; it 
consists of 1 part of powdered tragacanth and 7 parts of finely pow- 
dered (No. 80) elm bark. Only a very small proportion of the 
powder is required, thus : 3 grains for 60 grains of bismuth sub- 
nitrate, calomel, cerium oxalate, iron by hydrogen, or equal parts of 
camphor and lead acetate ; 6 grains of the powder for 60 grains of 
dried ferrous sulphate, the scale salts of iron, or equal parts of cam- 
phor and capsicum, etc. In all cases in which this excipient powder is 
employed, the mass should be made up rather soft with syrup, other- 
wise it is apt to crack or crumble while the pills are being formed ; 



PILLS. 313 

pills thus made become sufficiently firm and retain their original 
shape, ou account of the fibrous and adhesive character of the excip- 
ient. Hager has recommended a similar powder, composed of 1 part 
of powdered marsh mallow root, \\ parts of powdered tragacanth, 
and 6 parts of powdered orris root ; this powder cau be used like the 
precediug, and is better adapted to white pill-masses. In place of 
syrup, a mixture of two volumes of glycerin and one of distilled 
water may be used for pills which it is desired to keep soft. 

At oue time, crumb of bread was ordered quite frequently as an 
excipient for pill-masses, particularly in cases in which it was intended 
at the same time to serve as a vehicle for the administration of potent 
remedies, as in the case of mercuric chloride, strychnine, etc. In 
place of bread-crumb, which is not always available, either of the 
excipieut powders mentioued above may be used, or a mixture of 1 
part of tragacanth and 3 parts of starch, the mass to be made with 
glycerin and water, as before stated. The salts of quinine and cin- 
chonidine are frequently prescribed in pill form, in combination with 
aromatic or diluted sulphuric acid, the quantity of acid being often 
left to the judgment of the dispenser. As a rule, from one-third to 
one-half as much acid as alkaloidal salt, is sufficient to make a 
satisfactory mass, depending somewhat upon the condition of the 
atmosphere. The mass must be rolled out as soon as it becomes 
plastic, while still a little soft, otherwise it becomes dry and crumbly ; 
in the latter case, the addition of a drop or two of syrup, or a very small 
quantity of glycerite of starch, restores the proper condition. Quinine 
sulphate triturated with one-sixteenth of its weight of tartaric acid, 
becomes damp and adhesive, and, upon the further addition of a small 
quantity of glycerin (about 15 or 16 drops to 100 grains of quinine 
sulphate), yields an excellent mass, the pills being small and firm. 
If kept in a cool, dry place, such pills retain their original condition 
for a long time. Although strong mineral acids are very rarely 
prescribed in pills, they are occasionally used, in combination with 
pepsin and vegetable powders, in prescriptions coming from Ger- 
many ; the excipient powder mentioned in the preceding paragraph, 
together with glycerin and water, will yield a good mass. 

Easily reducible substances, like silver nitrate, potassium perman- 
ganate, silver oxide, gold chloride, etc., cannot be massed with the 
usual excipients, as they need some adhesive agent which will not 
cause decomposition. The most available substances are white clay 
(kaolin) and water, which form a plastic mass, but one requiring quick 
manipulation, as it soon becomes dry and crumbly. Recently, M. 
Carles has proposed a new excipient for pill masses of this character, 
namely, a mixture of 2 parts of kaolin and 1 part each of anhydrous 
sodium sulphate and water. Sixty grains of kaolin and 30 grains of 
the sodium sulphate require forty minims of water to form a plastic 
mass, which dries slowly and retains * its plasticity for six or eight 
minutes ; it admits of much better manipulation than clay and water 
alone, and the pills, when formed, soon become hard and retain their 



314 PRACTICAL PHARMACY. 

shape, owing to the assumption of the crystallized state by the anhy- 
drous sodium sulphate under the influence of water. When potas- 
sium permanganate is to be made into pills with this excipient, a larger 
quantity of water must be used ; the best plan is to rub 30 grains of 
potassium permanganate into fine powder, mix well with 30 grains 
of kaolin and 15 grains of anhydrous sodium sulphate and then 
mass with sufficient water, usually 25 to 30 miuims. A mixture of 
equal parts of kaolin, or Fuller's earth, soft petrolatum, and paraffin, 
forms a most excellent excipient for this class of pills, or the medi- 
cinal agent, in fine powder, may be incorporated with its own weight 
of lanolin, or wool fat, deprived of its water, and then sufficieut 
kaolin be added to form a mass. Lanolin is indifferent toward silver 
nitrate and potassium permanganate (Hager). Another satisfactory 
method is to mix potassium permangauate with one-half or the 
whole of its weight of kaolin and then mass with one-fourth its 
weight of soft petrolatum. 

When deliquescent substances, or such as slowly volatilize upon 
exposure to air, are ordered in pill form, a mixture of potassium 
borotartrate with half its weight of water will prove a good excipient; 
about oue-sixth of a grain of powdered tragacanth should be added 
for each pill, and the mass must be quickly formed and rolled out ; 
60 grains of chloral hydrate or 30 graius of potassium iodide require 
2 drops of the excipient. Even potassium acetate has been made 
into satisfactory pills by the aid of potassium borotartrate, 18 
parts of the former and 3 parts of the latter being used with 1 part 
of water. All such pills must be dispensed in bottles. 

The third class, absorbent excipients, are frequently required to 
supply the necessary firmness to a pill-mass, so that the original 
shape given to the pills may be retained. The addition of absorbeut 
powders must be made judiciously, so as to avoid an unnecessary 
increase in the bulk of the mass, and the quantity used should be 
noted on the prescription, so that in case of a repetition pills of 
the same size may be dispensed. The reckless use of solvent as well 
as absorbeut excipients is one of the chief errors of inexperience, 
and often causes much trouble. Some absorbent powders, such as 
starch, calcium phosphate, magnesium carbonate, liquorice root, and 
orris root, possess little or no adhesive properties, and, if used in 
excess will cause the mass to crumble ; others, like marshmallow 
root, acacia and elm-bark, containing much mucilaginous matter, if 
used in excess, form hard and slowly soluble combinations. 

For pill-masses containing an excessive quantity of soft, solid 
extracts, powdered liquorice root will be found very desirable and 
preferable to powdered elm-bark, unless metallic salts are present in 
large proportion. For volatile oils, creosote, and liquid oleoresins, 
soap is decidedly the best excipient, as it emulsionizes these and pre- 
vents their separation during subsequent manipulations; from one- 
half to one grain of soap is necessary for each minim of oil, and 
stearin or curd soap will be found preferable to olive-oil soap. In 



PILLS. 315 

the absence of any vegetable powder in the prescribed combination, 
the addition of powdered liquorice root is desirable, and a mixture 
of 1 part of soap and 5 parts of liquorice root forms a convenient 
excipient, of which 3 grains should be used for each minim of vola- 
tile oil; if necessary, water or diluted alcohol may be used to facili- 
tate massing. The incompatibility of soap and soluble metallic 
salts in pill-masses has already been noted in a previous paragraph. 
For creosote, when ordered by itself, powdered liquorice root and 
water are very serviceable ; 2 grains of the powder with a little water 
are sufficient for each drop of creosote. Carbolic acid can be treated 
like creosote, and soap will be found to bind it very nicely. 

Tar, when prescribed in pill form, either alone or in connection 
with other remedial agents, requires the addition of an absorbent ; 
magnesium carbonate aud powdered liquorice root have been recom- 
mended, but calcium phosphate, used in twice the weight of the tar, 
has been more satisfactory, yielding a firm yet plastic mass. Pills 
thus made retain their original shape and disintegrate quite readily in 
water. For making pills of mercurial ointment, the same excipient 
has been used with success. 

Hager has suggested a mixture of equal weights of yellow wax and 
starch, in the form of powder, as a superior adhesive and absorbent 
excipient for numerous troublesome pill-masses ; starched wax is 
decidedly preferable, as an excipient, to wax with an addition of some 
fibrous vegetable powder, as pills made with the former disintegrate 
more rapidly, and the wax, being in a state of fine division, is less 
liable to cause intestinal trouble. From 3 to 5 grains of starched 
wax will yield a satisfactory mass with 1 grain of each of the fol- 
lowing substances (Hager) : Carbolic acid, apiol, oleoresin of male 
fern, guaiacol, creosote, croton oil, terpinol, and oil of tar. Starched 
wax may be prepared by thoroughly drying yellow wax, in the form 
of thin shavings, under paper cover in a dark place, and then rubbing 
into powder with an equal weight of rice-flour. 

Unless some other substance is present, as an oleoresin or a volatile 
oil, whereby the melting-point of the mixture is brought down to 
about 38° C. (100.4° F.), wax is very undesirable in pill-masses on 
account of its difficult disintegration, which may cause pills made 
therewith to pass through the body unaltered. When wax is 
directed to be used in a pill-mass, it should be melted at a moderate 
heat and then mixed with any oil or oleoresin ordered, before the 
solid ingredients are added. 

Powdered tragacanth may sometimes be employed as an absorbent 
when it is desired to impart adhesiveness to a very moist mass, with- 
out materially increasing the bulk. The mixture of tragacanth and 
powdered elm-bark previously mentioued, is, however, generally to be 
preferred. The compound tragacanth powder of the British Pharma- 
copoeia, composed of 1 part each of powdered tragacanth, powdered 
acacia and starch, and 3 parts of powdered sugar, forms an excellent 
absorbent and adhesive excipient. These pills disintegrate readily. 



316 PRACTICAL PHARMACY. 

A mixture of equal parts of finely- powdered elm bark and starch 
will be found a most desirable excipient for soft pill masses contain- 
ing iodine or iodide of iron ; the mass should be rolled out while 
still moderately soft, as the pills will harden subsequently. Pill- 
masses containing free iodine should invariably be made with the 
addition of starch, which, combining with the iodine, prevents its irri- 
tating effect on the mouth and throat ; the union between the starch 
and iodine is very feeble, and the latter will be again liberated by the 
warm liquids of the stomach. 

In a few cases the addition of any excipient is superfluous, as when 
lupulin and camphor are ordered together in pill form. The simple 
trituration of powdered camphor with lupulin causes the resinous 
matter to soften, and an adhesive mass is quickly obtained, which 
hardens again on standing. All solvents, like ether, alcohol, and 
diluted alcohol, must be avoided, but a very small quantity of elm 
bark may sometimes be added with advantage in very warm 
weather. 

Mortars and other utensils used in making pill-masses are some- 
times cleaned with great difficulty, on account of the stain imparted 
by certain chemicals. As a rule, plain water, cold or hot, will suffice 
to remove the slight remnants of a pill-mass, especially if allowed to 
stand in the mortar for a short while, but in some cases the addition 
of lye (caustic potassa or soda solution) becomes necessary to soften 
hard resinous deposits. The persistent odor of volatile oils is best 
removed with a little alcohol, after the mortar has been well washed 
with water. A few drops of oil of turpentine very promptly re- 
move the peculiar odor of iodoform. Metallic stains, as a rule, 
are dissolved quickly by a little strong hydrochloric or nitric 
acid. Manganese dioxide stains disappear at once, if treated with 
coarsely powdered ferrous sulphate, sulphuric acid, and water, while 
potassium permanganate stains yield readily to a solution of oxalic 
acid. 

Division of the Pill-mass. After the mass has been properly 
prepared it is transferred to a regular pill-machine or a graduated 
glass or porcelain tile, to be rolled out, by means of a flat piece of 
hard wood, into a cylinder of uniform thickness, which is then 
divided into the requisite number of pieces. Steel spatulas are 
used by many for rolling out the mass, but are not so desirable as a 
wooden roller, since the width of the spatula permits of covering only 
a small part of the mass at a time, hence irregularity in the thickness 
of the cylinder frequently occurs. A little pressure must be applied 
when rolling the pill-cylinder. Figs. 211 and 212 represent wooden 
pill-mass rollers, the long one with the handle having the more 
convenient shape. 

A small number of pills may be conveniently divided on a pill- 
tile (Pig. 213), but, for a larger number, a pill-machine will be found 
preferable, particularly if the weight of the pills corresponds to the 
size of the grooves, for then the perfect rounding of the pills can be 



PILLS. 



317 



readily effected by continued rolling in these grooves. Fig. 214 repre- 
sents a complete pill-machine. It consists of a smooth, hard wood 
rolling-board encased in metal and provided with a grooved metal 
plate ; to the roller, which is likewise made of hard wood, is attached 



Fig. 211. 



Fig. 213. 




Fig. 212. 



Pill-roller. 



I. . ; 

Wooden pill-roller. 




Pill-tile, graduated. 



a similar metal plate, the grooves of which correspond exactly to the 
grooves of the plate on the board, being adjusted to the size of pills 
of certain weights, as 1,2, 3, or 5 grains. To facilitate the motion of 
the roller it is frequently provided with two little metal wheels on each 
side of the grooved plate, as may be seen in the illustration. When 



Fig. 214. 




the roller is in use, these bear against the metal casing of the rolling- 
board, and thus enable the roller to travel uniformly. 

The best pill-machine is the "Cooper patent" (Fig. 215), the 
woodwork being of mahogany and the metallic parts of brass. This 
machine has two sets of reversible grooved plates, on which four 
different sizes of pills can be made — 1, 2, 3, and 5 grains; the 
plates being quickly removable and adjustable. The sides of the 



318 



PRACTICAL PHARMACY. 



rolling-board are so constructed that they can be raised or lowered 
by means of winged screws, which allows the mass to be rolled just 
the thickness required for each respective size of pills, thereby insur- 
ing always the full number of perfectly round pills. 



Fig. 215. 




The Cooper Patent Pill-machine. 



Fig. 216. 



After the cylinder has been properly rolled out to the length of 
the desired number of pills, it is placed upon the grooved plate of 
the board, and divided by applying the other cutter and drawing 
this forward and backward with slight pressure. 

When the pill-cylinder is divided on a pill-tile, and also when the 
pills are larger or smaller than the grooves of the machine, it be- 
comes necessary to impart a spherical shape to the pieces, by appro- 
priate rolling between the thumb and first and second fingers, after 
which the pills should be placed under a pill-finisher and completely 
rounded by rotary motion of the same with some pressure. It is 
better to move the finisher about in curvilinear figures like the 
figure 8, instead of giving it a constant cir- 
cular motion, so that the pressure may be 
uniform at all points. Pill-finishers usually 
consist of a circular piece of hard wood, with 
a smooth rolling surface and a projecting 
margin for the purpose of confining the 
pills ; several sizes are required to suit dif- 
ferent sizes of pills. Fig. 216 represents a 
convenient pill-finisher suitable for two different sizes, as the upper 
and lower margins project to different lengths. 

Pill-dusting. The pill mass, being plastic and adhesive, is apt 
to adhere to the slab and the fingers while being rolled out and 
shaped into pills. This may be prevented by the use of a fine 
powder, which should be strictly inert, unless otherwise directed by 
the physician. Among the most suitable powders are lycopodium, 
liquorice root and starch. The former is particularly desirable on 
account of its fineness and uniformity, its slight adhesiveness and its 
utter tastelessness. Powdered starch should be used with all white 
pill-masses, Bermuda arrow-root being the best for the purpose. 




Hard-wood pill-finisher. 



PILLS. 



319 



Fig. 217. 



Only in exceptional cases is the addition of dusting-powder to the 
pills in the box justifiable ; the pills should receive a sufficient coat- 
ing of the powder under the finisher, then, if the mass has been prop- 
erly made, there will be no danger of the pills adhering, hence no 
occasion for putting an excess of powder in the box. Magnesia 
and magnesium carbonate are not well suited for dusting-powders, 
and should, moreover, be used with due care, on account of the 
possible chemical effect upon the ingredients of the pills. Powdered 
talc (soapstone) is likewise serviceable, having the advantage of 
imparting a very thin, opaque and tasteless coating to the pills, 
without impairing their solubility in the stomach; it is particularly 
suited for pills of silver nitrate and the like. When asafetida or 
other nauseous substances are given in the form of pill, the odor 
may either be entirely covered or considerably modified by the use 
of powdered cinnamon, aromatic powder, ginger, or similar material. 

Pill-coating. The plan of coating pills with various substances, 
with a view of disguising the odor and taste of nauseous mediciues, 
is by no means a novelty, having been practised over fifty years ago. 
At one time, the silvering or gilding of pills was of frequent occur- 
ence, but at present it is but rarely employed. Pills to be thus 
coated must be made firm and rolled per- 
fectly smooth, if possible, without any 
dusting-powder ; they should be slightly 
dampened w T ith very thin mucilage of 
acacia and then placed in a suitable ap- 
paratus consisting of two hollow 7 hemi- 
spheres of hard wood or horn, as shown 
in Fig. 217. Silver or gold foil is added, 
when, the apparatus having been closed, a 
rapid rotary motion will, in a very short 
time, cause the pills to take on a uniform 
coating of the metal ; should some of the 
pills receive only a partial covering, more 
foil must be added and the rotary motion 
repeated. As a rule, one leaf of silver or 
gold will cover a dozen two-grain pills. 

Glycerin should not be used as an excipient for pills which are to 
be silver- or gold-coated, as it will lessen the brightness of the metal. 

Sugar-coating is a process which is not readily applicable to the 
operations of the pharmacist, requiring experience and practice to 
insure success. It partakes of the confectioner's art, although the 
coating of pills with sugar requires somewhat more care, on account 
of the absence of starch or flour, which generally make up a part of 
the confectioner's coating. Sugar-coating of pills is done, on a large 
scale, in hemispherical copper pans made to revolve slowly within a 
coil of steam-pipe supplying the necessary heat for evaporation of 
the moisture ; the pills, which should be well air-dried, are placed 
in the pan, and a quantity of simple syrup or of a mixture of syrup 




320 



PRACTICAL PHARMACY. 



and mucilage of acacia is poured on, the pan being kept in constant 
rotary motion until the pills are dry. The addition of syrup is 
repeated until a sufficiently thick coating has been deposited on the 
pills, and this can only be ascertained by experience. 

Sugar-coating can be more successfully performed with a large 
quantity of pills than with a small number, as the deposit of sugar 
takes place more uniformly, and the mutual attrition of many pills 
insures a smooth surface. Fig. 218 represents a sugar-coating pan 
in use in large manufacturing establishments ; as seen in the illus- 
tration, it is operated entirely by steam-power. For small oper- 
ations it will be found desirable to dampen the pills with diluted 

Fig. 218. 




Sugar-coating machine for pills. 



mucilage of acacia or egg-albumen and then rotate them in a 
tinned-copper or porcelain dish containing either finely bolted sugar 
or a mixture of acacia 1 part and sugar 5 parts, or of sugar 2 parts, 
sugar of milk 1 part and purified talcum 1 part. With care and 
practice, very fair results may be obtained, although the pills can- 
not be expected to look as perfect as those coated by machinery. A 
small apparatus has been devised in England for facilitating the 
sugar-coating of pills at the dispensing counter ; it is shown in Fig. 
219 and consists of a flat-bottomed, tinned-copper pan, with a 
hinged cover. The pills having been dampened as directed, may be 
placed in the pan with the sugar and rotated while a gentle heat is 
applied, which facilitates the drying of the coating; when dry, the 



PILLS. 321 

process can be repeated until a perfect, hard, white coating is ob- 
tained. Sugar-coated pills do not at first have the glossy appear- 
ance so familiar to all, but are dull when takeu from the coater ; 
they are then shaken with pieces of paraffin, which causes a minute 
film of the latter to be deposited ou the sugar, and thus the desired 
gloss is produced. 

Fig. 219. 







Small sugar-coating pan. 

Gelatin-coating is more readily applied than sugar-coating, but, 
like the latter, requires practice to insure proficiency. The chief 
difficulty lies in the drying of the coating after the pills have been 
dipped into the solution of gelatin ; the pills must be kept in motion 
while the gelatin cools, otherwise the coating will not be uniform. 
Pills to be gelatin-coated must be firm, dry and free from dusting- 
powder ; if glycerin is used as an excipient, it is apt to soften the 
gelatin-coatiug, causing the pills to stick together. For pills con- 
taining strongly odorous substances, such as asafetida, sumbul, iodo- 
form, the valerianates, etc., gelatin-coating is decidedly inferior to 
sugar-coating, as the odor very soon penetrates the gelatin. The 
manner of coating the pills on a large scale is identical with that 
used for only a dozen pills, namely, the pills are impaled upon long 
thin needles, to the depth of about -^ of an inch, and then immersed 
in a solution of gelatin kept fluid by means of a water-bath ; in 
order to avoid contraction and cracking of the gelatin upon cooling, 
mucilage of acacia is usually added to the solution, and, by some, 
syrup also. The rapid drying, on a large scale, is effected by placing 
the pills, soon after they have been dipped, while still on the needles, 
in specially constructed drying cases connected with an exhaust fan, 
by means of which, air is rapidly drawn through the cases, and the 
moisture is thus removed. 

For small operations, various devices have been suggested for dry- 
ing the gelatin-coating, no one of which can be said to be the best, as 
pharmacists are apt to prefer that apparatus with which they have 
become most familiar by practice. The gelatin solution should be 
kept at a temperature between 72° and 82° C. (161.6° and 179.6° 

21 



322 



PRACTICAL PHARMACY. 



F.), so that it may not be too thick when the pills are immersed, and 
any scum or froth forming should be carefully pushed aside before 
the pills are dipped. Figs. 220, 221, 222 and 223 represent the four 
leading styles of gelatin-coating apparatus in use among pharmacists 
in this country. In three of them the pills are taken up on the needles 
from a tray provided with grooves, in which the pills have been 
placed, and, after they have been dipped into the gelatin solution, 
are revolved until dry and then stripped from the needles by 
means of a comb, shown in the illustrations. The arrangement of 
Prof. Patch for drying the coating, consists of a wheel with slots, 
in which the bars carrying the needles are placed, when the wheel is 
made to move alternately in opposite directions, by means of a string 
attached to the axle passing through the wheel (see Fig. 220). The 
gelatin solution recommended by Prof. Patch is made as follows: 

Fig. 220. 




Prof. Patch's gelatin-coater. 



Macerate 2 J ounces (av.) of French gelatin (gold label) with 7 fluid- 
ounces of distilled water, and, when soft, dissolve by aid of a hot 
water bath ; add 2 drachms of boric acid and finally 2 fluidounces of 
mucilage of acacia ; strain the mixture. 

The "Porcupine" gelatin-coater (Fig. 221), designed by C. C. 
Wells, consists of a wooden tray, A, provided with grooves and a 
gauge for regulating the depth to which the needles shall enter pills 
of different sizes, and also a brass comb for disengaging the pills from 
the needles ; a drying cylinder, B, provided with T-shaped rails on 
its rounded cylinder, which form grooves for receiving the needle- 
bars, C; a water-bath and solution holder, _D, the latter being a 
trough in the cover of the bath and kept at the right temperature by 






PILLS. 



323 



the aid of heat. After the needle-bars carrying pills have been 
placed in the grooves of the cylinder the latter is kept revolving, by 
means of the crank on the side (larger machines are operated by 



Fig. 221. 





Wells' " Porcupine " gelatin-coater. 

clock-work attachments), at the rate of about 50 revolutions a minute, 
until the pills are dry enough not to stick together when taken off 
the needles. Wells recommends the following solution for gelatin- 
coating : Dissolve 2 drachms of acacia in 1 fluidounce of water and 
add 1 ounce (av.) of Cox's gelatin, 2 fluidounces of water and 1 fluid- 
ounce of simple syrup ; dissolve by heat and strain. 

The gelatin-coater of W. C. Franciscus (Fig 222), resembles the 
other two, except in the provision for drying the coating on the pills, 
which must be done by rapidly twirling the needle-bars centred on a 
pivot, w 7 ith the hand, until the pills are sufficiently dry to be re- 
moved. The different steps of the operation are shown in the illus- 
stration ; A represents a water-bath, and C the solution-holder rest- 
ing in the same ; B B shows the position of the needle-bar in the 
act of impaling the pills which have been placed in the depressions 
in the tray, the balls on the ends of the bar insuring accuracy in 
centring the pills with the needle-points, by slipping over the rods 
B and B. At E is shown the manner of revolving the pills, after 
they have been dipped, by means of the pivotal handle, D. When 
sufficiently dry, the pills are stripped from the needles by means of 
the comb attached to the tray, G. 



324 



PRACTICAL PHARMACY. 

Fig. 222. 




Franciscus' gelatin-coater. 



Maynard's gelatin-coater (Fig. 223) is not provided with a grooved 
tray from which the pills are taken up, but, instead, the pills are 
placed in depressions in a metallic plate, E, provided also with two 



Fig. 223. 




Maynard's gelatin-coater. 

holes to receive the guide-pins attached to the circular needle-holder, 
D, and surrounded with a metallic ring, F, to keep the pills from 
rolling off. When the needle-holder is not in use, the needle-points 
are drawn back behind the outer disk by means of the handle 
attached to the top, to which the needles are fastened. To impale 
the pills, the needles are depressed, passing through the perforations 
in the outer disk, and take up the pills as shown at C. The gelatin 
solution is contained in a covered agate-ware dish, resting in the 
copper water- bath, A; after the pills have been dipped, the needle- 
holder is slowly revolved to facilitate the uniform distribution of the 



PILLS. 



325 



gelatin film. When the gelatin has set, the needle-holder may be 
laid aside, as shown at C, until the coating is sufficiently hard to 
allow the pills to be removed to the tray of Avire gauze, B, by 
grasping the circular plate on the needle-holder with one hand and 
pulling the handle upward with the other. It is always well to 
slightly grease the perforated disk, through which the needles pass, 
with petrolatum, to prevent the pills from adhering. 

The application of a continuous coating of gelatin to pills without 
the use of needles is in successful operation at several large manu- 
facturing establishments, but is not available at the dispensing coun- 
ter, since extensive steam-power machinery is necessary for the work. 
In Fig. 224 may be seen a cut of probably the only machine of its 



Fig. 224. 




Colton's machine for continuous gelatin-coating. 

kind at the present time; it was designed by Arthur Colton, of De- 
troit, Michigan, and has a capacity of coating from 6000 to 10,000 
pills per hour. This ingeniously constructed piece of machinery is 
operated by two female attendants in the following manner : The 
pills to be coated are placed in the drawer J., which is provided 
with a perforated plate in the bottom at the end projecting from the 
drying-kiln. The drawer A having been drawj out and so arranged 
that the perforated plate registers over a set of tubes on plate B, the 
pills are brushed through the perforations by means of a brush mov- 
ing forward and backward in A, and are firmly held on the tubes 
by a vacuum, produced by means of t-he pump, P. The tube-plate, 
B, is fastened by meaus of a clamp to the hood, C, and by revolving 
the latter half way the plate is brought face downward over the pan, 



326 PRACTICAL PHARMACY. 

D, containing the gelatin solution. By means of the handle, E, the 
pan, _D, is then slowly raised far enough to immerse the pills half 
way, which is regulated by the stop, F, so as to avoid getting any 
gelatin solution on the tube- plate. The plate, B, with the pills, is 
next raised and carefully placed in the slide, G, and another tube- 
plate filled with pills as before, the operation of placing the pills on 
the tubes and coating them beiug continued until the supply is 
exhausted. As one plate after another is placed in G they are 
pushed forward through the kiln, where the coating is dried by cur- 
rents of warm air sufficiently to allow the pills to be transferred to 
another plate at the other end, when the operation of dipping the 
other half of the pills is performed by the second attendant, and the 
plate now carrying the completely-coated pills is returned through 
the kiln on a second slide running parallel to the first. When the pills 
again reach the first operator they are dry enough to be placed into trays. 

In place of gelatin -coating at the dispensing counter, the plan pre- 
vails, in this country, of disguising the disagreeable odor and taste of 
pills by enclosing them in gelatin capsules. These gelatin capsules 
are sold under the name of empty capsules, and consist of small 
cylinders closed at one end and provided with a shorter cylindrical 
cover ; they occur in seven sizes, ranging from f inch to 1 inch in 
length, and are numbered respectively from No. 5 to No. 00 ; they 
are sold at fabulously low prices. The composition of the empty 
capsules made in this country is a mixture of gelatin and glycerin in 
variable proportions, dependent upon the character of the gelatin. 
The French Pharmacopoeia recommends for hard capsules a mixture 
of 30 parts each of white gelatin, gum arabic, and sugar, 10 parts of 
clarified honey, and 100 parts of water, to be melted with the aid of 
a water-bath ; for elastic capsules is recommended a mixture of 50 
parts of white gelatin, 15 parts each of gum arabic and sugar, 12J 
parts of glycerin, and 80 parts of water, to be likewise dissolved on 
a water-bath. Other authorities propose for hard capsules a mixture 
of 60 parts of gelatin, 10 parts each of acacia and sugar, aud 50 
parts of water ; and for soft capsules a mixture of 50 parts of gelatin, 
16 parts of sugar, 20 parts of glycerin, and 90 parts of water. 

The capsules are made by dipping either metallic, bone, or wooden 
moulds, attached by means of handles to a suitable disk, into the 
melted gelatin mass kept at a temperature of about 40° C. (104° F.), 
and then rotating the moulds gently for a few minutes so as to insure 
a uniform film ; if necessary, the immersion is repeated. To prevent 
adhesion of the gelatin solution to the moulds, the latter are rubbed 
with a soft oiled cloth before dipping them. After twenty or thirty 
minutes the gelatin film will have become sufficiently firm to allow 
the capsules to be stripped from the mould, and laid aside to dry in 
suitable closets provided with a draft of moderately warm air, any 
excess of gelatin being removed with an ivory knife before the cap- 
sule is taken from the mould. 

As the object of capsuling pill-masses is to render the medicine 



PILLS. 327 

as palatable as possible, care should be taken that the exterior of the 
capsule be not contaminated in any way with the material. This is 
best accomplished by dividing the mass into small cylindrical pieces, 
rounding off the ends of each, and then, after having washed the 
hands thoroughly, introducing the pieces, by the aid of a long needle, 
into the capsule held in the left hand, taking up the cover with two 
fingers of the right hand holding the needle and quickly slipping it 
into position, thus avoiding all contact of the mass with the exterior 
of the capsule. The habit of putting pills into capsules with the 
finders is censurable and an evidence of bad training. 

The filling of capsules with liquids is, as a rule, done in large 
manufactories, and, for this purpose, capsules of ovoid shape hav- 
ing a small orifice are selected ; they are supported on trays or racks, 
and the liquid is introduced by means of a pipette or a syringe with 
a small nozzle. The orifice of the capsule is finally closed by putting 
over it a little of the warm gelatin solution, with a glass rod. When 
the pharmacist has occasion to dispense liquids in ordinary empty 
capsules the best plan is to set the capsules up in a shallow box with 
a perforated lid, and, having introduced the liquid, seal the cover 
hermetically by moistening the edges in a drop of water spread on a 
pill-tile, before slipping it over the capsule; a mere trace of water 
being sufficient to cause a union between the cover and the capsule, 
any excess of moisture must be shaken off, as it would cause the 
capsule to soften and finally leak. 

The well-known French pearls of ether, apiol, chloroform, etc., 
are gelatin globules filled with the respective liquids. According to 
Th6venot, they are prepared as follows : A mass composed of gelatin, 
acacia, sugar, and honey, is rolled out into thin sheets, one of which, 
while still soft, is placed upon an iron plate of 6 millimeters (about 
J iuch) thickness, and containing numerous suitable cavities of 10 
millimeters (about f inch) diameter, into which the mass sinks by 
reason of its own gravity, thus forming a hollow hemisphere in each 
cavity; the desired liquid is introduced by means of a pipette or 
small syringe, and a cover consisting of another sheet of the same 
gelatin mass is laid on. A second iron plate corresponding exactly 
to the one first used, is now placed over the last sheet, and, after 
screwing the plates together their position is reversed so that the 
second gelatin sheet may fill the cavities in the second iron plate, 
thus completing the spherical shape of the pearls or globules, which 
are finally separated from each other by subjecting the whole arrange- 
ment to powerful pressure. 

Another method is said to consist in filling a tube, made of gelatin 
composition, with the respective liquids, and then, by means of a 
specially constructed machine, cutting off pieces of the required size 
and simultaneously pressing these into the proper shape. The ap- 
paratus used for this method was invented by a French pharmacist 
and is known as Viel's Capsulator. 

Pills are sometimes coated with collodion or balsam of tolu ; the 



328 PRACTICAL PHARMACY. 

latter plan is directed in the official formulas for pills of iodide of 
iron and of phosphorus. To coat pills with collodion, they are 
simply impaled on needles and dipped into collodion, which is then 
allowed to dry ; if water be present in the pills, the coating will 
become mottled or opaque. The Pharmacopoeia directs a solution of 
10 Gm. of balsam of tolu in 15 Cc. of ether, for coating pills, but, 
owing to the very rapid evaporation of the solvent, the process is 
very unsatisfactory, as the pills are apt to stick. A better plan is to 
follow the suggestion of Prof. Patch, which is as follows : Dissolve 
540 grains of balsam of tolu and 180 grains of mastic in 2 fluid- 
ounces of alcohol, and filter through cotton. Coat the interior of 
two flat evaporatiug dishes with a very thin film of oil of sweet 
almond or petrolatum, place the pills to be coated in one of the dishes, 
add a few drops of the solution, cover with the second dish and 
rotate rapidly until the pills are well coated, then put on a tray to dry. 

The so-called "pearl coating" is applied in a manner similar to 
that used for gildiug or silvering ; the pills having been evenly 
dampened with a very thin adhesive liquid (mucilage of acacia 5j, 
syrup 5j, and water 5vj, or tragacanth 4 grains, syrup 5ss, and 
water 5vijss), are rotated in a globular box with purified talcum or a 
mixture of talcum and sugar in the form of an impalpable powder. 
If a high polish is desired, this can be obtained by rotating them 
afterward in another globe coated on the inside with paraffin. 

Keratin coating has been especially recommended for pills which 
are not to be acted upon in the stomach, but to be soluble in the 
intestinal fluids. Keratinized pills were first introduced by Dr. 
Unna, of Germany, but have not met with much favor, on account 
of the tedious process of coating. Keratin is a constituent of all 
horny matter and is obtained from the same, after removal of fat 
with ether, by digestion in the form of shavings or turnings, with a 
mixture of pepsin, hydrochloric acid, and water, for twenty-four or 
thirty-six hours ; this treatment removes all matter soluble in the 
gastric juice. The residue, having been well washed with water, is 
digested with eight or ten times its weight of 5 per cent, ammonia 
water in a loosely stoppered flask, at a moderate heat, until a nearly 
complete solution results, which is then filtered and evaporated to 
dryness. Keratin, as thus prepared, is a commercial article ; both 
acid and alkaline solutions of it are used for coating pills. 

Ammoniacal solution of keratin is prepared by dissolving 7 parts 
of keratin in a mixture of 50 parts of 10 per cent, ammonia water 
and 50 parts of 60 per cent, alcohol (solution may be facilitated by 
warming). This alkaline solution should be used for pills containing 
trypsin, pancreatin, metallic sulphides, etc. 

Acetic solution of keratin, made by dissolving 7 parts of keratin 
in 100 parts of glacial acetic acid (if necessary, by the aid of a 
moderate heat), is adapted for pills containing ferric chloride, tannin, 
salicylic acid, arsenic, creosote, and the salts of mercury, gold, and 
silver. 



PILLS. 



329 



For chemically indifferent substances, either the alkaline or acid 
solution of keratin may be employed. 

All pills intended to be coated with keratin must be made with 
some fatty excipieut and contain no appreciable moisture ; the mass 
is best made with cacao-butter and oil of sweet almond, or a mixture 
of purified mutton-tallow or cacao-butter 10 parts and white or 
yellow wax 1 part. After the pills have been rounded they should 
be dipped iu melted cacao-butter, which is allowed to harden ; they 
are then placed in a porcelain dish, the keratin solution added (about 
30 or 40 drops for 100 pills of medium size) and rotated until the 
pills have become thoroughly moistened, after which they are dried 
on parchment paper, to which they will not adhere. The application 
of keratin solution must be repeated three or four times and allowed 
to dry each time. 

To avoid the tediousness of coating with keratin, salol coating has 
been recommended, which is best applied by melting salol in a dish 
and dipping the pills, fixed on needles, into it, afterward closing the 
small needle-holes separately. Salol, like keratin, is insoluble in the 
gastric juice, but the coating has not been found so satisfactory. 



The Official Pills. 

The U. S. Pharmacopoeia gives working formulas for 15 varieties 
of pill-masses, and as these are directed to be divided into a definite 
number of pills, they are indicated under the title " Pilulse." The 
term "Massa" is applied to those combinations which are intended 
to be kept on hand in bulk, being frequently prescribed as constitu- 
ents of other pill-masses. In the British Pharmacopoeia 21 formulas 
for pill- masses are given, but in no case is the mass directed to be 
divided into a given number of parts ; they are all designated by 
the simple title "Pilula." 



Alphabetical List of the Official Pills. 

Name. Composition of each Pill. 

Pilulfe • \loes / Purified Aloes ' • • °- 13 Gm - 
l-iiuife. Aloes . . ^ Soap 0.13 " 

r Purified Aloes . . . 0.09 Gm. 
Aloes et Asafcetidae \ Asafetida .... 0.09 " 
I Soap 0.09 " 

Purified Aloes . . . 0.07 Gm. 
Aloes et Ferri . . -! Dried Sulphate of Iron . . 07 " 
Aromatic Powder . . . 0.07 " 

Purified Aloes . . .0.13 Gm. 

Aloes et Mastiches \ Mastic 04 " 

Red Rose .... 0.03 " 

r Purified Aloes . s . . 0.13 Gm. 

Aloes et Myrrhse . \ Myrrh 0.06 " 

I Aromatic Powder . . . 0.04 " 



Excipient. 

Water. 
Water. 



Confection 
of Eose. 



Water. 



Syrup. 



330 



PRACTICAL PHARMACY. 



Pilulse: Antimonii 
Composite 

Asafoetidse . 



Catharticse 
Composite . 



Cathartics 

Vegetabilds 



Ferri Carbonatis 

r 



Ferri Iodidi 

Opii . . . 
Phosphori . 
Ehei . . . 



Composition of each Pill. 

f Sulphurated Antimony . . 0.04 Gm. 

^ Mild Mercurous Chloride . 0.04 " 

[ Guaiac 0.08 • 



Asafetida 
Soap 



Comp'd Extract of Colocynth 
Mild Mercurous Chloride 
Extract of Jalap . 
Gamboge .... 

Comp'd Extract of Colocynth 
Extract of Hyoscvamus 
" Jalap*. 
" " Leptandra . 
Eesin of Podophyllum . 
Oil of Peppermint . 

Ferrous Sulphate, crystallized 
Potassium Carbonate 
Sugar ..... 
Tragacanth .... 
Althaea 



Reduced Iron 

Iodine . 

Glycyrrhiza . 

Sugar 

Extract of Glycyrrhiza 

Acacia . 

Powdered Opium . 
Soap 

Phosphorus . 
Althaea . 
Acacia . 

Rhubarb 
Soap 



20 Gm. 
0.06 " 

0.08 Gm. 
0.06 " 
0.03 " 
0.015 " 

0.06 Gm. 
0.03 " 
0.03 " 
0.015 " 
0.015 " 
0.008 Cc. 

0.16 Gm. 
0.08 " 
0.04 " 
0.01 " 
0.01 " 

0.04 Gm. 
0.05 " 
0.04 " 
0.04 " 
01 " 
0.01 " 

065 Gm. 
0.02 " 

0.0006 Gm. 
0.060 " 
0.060 '• 

0.20 Gm. 
0.06 " 



Rhei Compositae 



Rhubarb .... 0.13 Gm. 

Purified Aloes . . . 0.10 " 

Myrrh 0.06 " 

Oil of Peppermint . . 0005 Cc. 

Special Remarks. 



Excipient. 

t Castor Oil. 
| Water. 

[ Water. 
Water 



j_ Glycerin 
and Water. 



\- Water. 



| Water. 

[ Glycerin 
| and Water. 




If it is desired to keep any of the official pills in stock in an un- 
coated condition, they should at once be placed in a mixture of lyco- 
podium and powdered liquorice root and allowed to remain there 
until dry, which may require from four to eight days ; they can then 
be kept in bottles, without danger of moulding or losing their shape. 
This plan is particularly advisable for the Compound and Vegetable 
Cathartic Pills. 

Pilulce Aloes et Asafcetidce. Select tears of asafetida only should 
be used, and it will be found advantageous to make a plastic mass 
of the gum-resin and soap with a small quantity of water, and then 
incorporate the powdered aloes. Excess of moisture must be care- 
fully guarded against. 

JPilulo3 Aloes et Mastiches. These pills, commonly known as Lady 



PILLS. 331 

Webster Dinner Pills, are apt to become very hard in time, hence it 
appears preferable either to make them up fresh when wanted or to 
use a mixture of syrup aud water, equal parts, or glycerin and water, 
equal parts, in place of water as an excipient. The mastic must 
be used in fine powder, and the three powders should be well mixed 
before any excipient is added. 

Pilulce Antimonii Compositce. These pills were at one time exten- 
sively prescribed under the name of Plummets Alterative Pills, and 
prescriptions calling for 100 pills at a time were not unusual. The 
use of castor oil as au excipient in place of mucilage of tragacanth is 
a decided improvement, and was taken from the British Pharma- 
copoeia. A little care is necessary to avoid an excess of oil, which 
renders the pills soft and greasy. After the powders have been well 
mixed, the castor oil should be added, a few drops at a time, and the 
mixture well kneaded after each addition, until a firm mass is ob- 
tained which is not greasy to the touch. It must be borne in mind 
that the oil acts as a solvent upon the resin, which, thus becoming 
soft, can be readily combined into a mass with the metallic powders. 
The stain left in the mortar when making Plummer's Pills is best 
removed with soap and water (preferably hot), followed by hydro- 
chloric acid. 

Pilulce Catharticce Compositce. In making these well-known pills, 
powdered extract of jalap is to be preferred to the pilular extract 
officially directed ; it should be first mixed with the gamboge and 
calomel and finally with the powdered compound extract of colo- 
cynth. A moderate quantity of water (fl5vi for 1000 pills), which 
should be added to the powders all at once, suffices to make a satis- 
factory, firm mass, provided the mixture be well kneaded in the 
mortar. Compound Cathartic Pills should never be put away in 
stock bottles until perfectly dry and hard. 

Pilulce Ferri Carbonatis. — Blaud's pills, as the official pills of 
ferrous carbonate are more commonly termed, have probably caused 
inexperienced pharmacists more trouble than any other pill-mass ; 
this is partly owing to the fact that physicians frequently order equal 
parts of ferrous sulphate and potassium carbonate, which renders the 
mass very deliquescent, on account of the excess of potassium car- 
bonate. The official formula yields very satisfactory results, the 
secret of success lying in the completed reaction between the iron 
aud potassium salts, before the final massing with tragacanth and 
althaea. The mass should be rolled out and cut while still moder- 
ately soft. The official formula is based on the assumption that 
absolutely pure potassium carbonate will be used, in which case the 
decomposition will be complete, as the 16 Gm. of crystallized ferrous 
sulphate require 7.954 Gm. of potassium carbouate, yielding 6.673 
Gm. of ferrous carbonate ; if the potassium carbonate used be less 
than 100 per cent, pure, an excess of ferrous sulphate will be present. 

Physicians are in the habit of prescribing four drachms each of 
ferrous sulphate and potassium carbonate to be made into 100 pills, 



332 PRACTICAL PHARMACY. 

which proportions should be changed to 4 drachms and 140 grains 
respectively. The following method of procedure, which I have 
used with marked success for many years, was, I think, first sug- 
gested by Mr. Tscheppe, of New York : Rub the 240 grains of 
crystallized ferrous sulphate into a fine powder with 30 grains of 
sugar, and mix with 140 grains of potassium carbonate also reduced 
to powder ; the mixture, which will soon soften and change color, 
should be stirred from time to time until the reaction is complete, 
which is known by the disappearance of the granular condition and 
the formation of a green, smooth, very soft paste. Nov/ add 30 
grains each of powdered starch and powdered acacia, mass quickly, 
and roll out while still soft, as the mass rapidly becomes firm and 
may then crumble when rolled out. 

Blaud's pills are intended to contain about 0.0667 Gm. (about 1 
grain) of ferrous carbonate, and cannot be kept on hand uncoated on 
account of the tendency to rapid oxidation of the iron salt, which is 
retarded, but not entirely obviated, by the sugar or sugar and glycerin 
present. The pills should be of a uniform deep green color, and are 
best prepared fresh when wanted. In Great Britain, the mass for 
Blaud's pills is officially recognized by the simple term " Pilula Ferri," 
and its composition is about the same as that published in our own 
Pharmacopoeia. 

Pilulce Ferri Iodidi. The official pills of ferrous iodide are pre- 
sumably identical with Blancard's Pills ; they contain an excess of 
iron, which aids in their preservation. Each pill is designed to 
contain about 0.0610 Gm. (about 1 grain) of ferrous iodide. Owing 
to the heat generated by the union of the iodine with the finely- 
divided iron, the former should be added slowly, so as to avoid loss 
by vaporization, and the mixed powder should not be added until 
all traces of free iodine have disappeared. When the mass has been 
evaporated to a proper consistence on a water-bath it will weigh 
about 20 Gm. The 5 Gm. of iodine ordered in the official formula 
require 1.104 Gm. of absolutely pure iron to form ferrous iodide; 
the amount of iron in excess will, therefore, depend upon the purity 
of the reduced iron used. 

Since pills of ferrous iodide are not, as a rule, made extempora- 
neously, and are readily affected by air and moisture, the Pharmaco- 
poeia very properly directs a resinous coating to be applied; the 
advantage of a solution of balsam of tolu and mastic in alcohol 
over an ethereal solution of balsam of tolu has already been referred 
to on page 328. 

Pilulce Phosphori. The uniform distribution of phosphorus in a 
pill-mass is best effected in a state of solution, and the choice of chlo- 
roform as a solvent in the official formula has a double advantage. 
Chloroform, besides being one of the best solvents for phosphorus 
known, is readily dissipated, owing to its very volatile nature, leav- 
ing the phosphorus, in a very finely divided form, intimately distrib- 
uted throughout the mixed powders, whilst its heavy, non-inflammable 



PILLS. 333 

vapor hovers over the mortar during the making of the pill- mass, 
thus protecting the phosphorus against oxidation. Phosphorus, 
being very inflammable, must be cut and weighed under water, hence 
the weighing of small quantities is often attended with much diffi- 
culty. A small glass capsule, or a watch-crystal, containing some 
water, should be carefully tared, and in it the phosphorus, having 
been cut into small pieces under water with a penknife, should be 
weighed ; the pieces may be removed with a small pair of forceps, 
quickly dried by means of filtering paper, and then dropped into the 
chloroform contained in a test-tube. 

Phosphorus is rapidly oxidized, particularly in a state of fine 
division, hence pills of phosphorus should be coated as soon after 
they have been made as possible ; as in the case of pills of ferrous 
iodide, the alcoholic solution of mastic and balsam of tolu is pref- 
erable to the official ethereal solution. 

Each pill contains 0.0006 Gra. (practically yj-g- grain) of phos- 
phorus. 

Pilulce JRhei Composite. Compouud pills of rhubarb will become 
very hard by age, and as they are not often called for, it is decidedly 
better to keep the ingredients properly mixed, in a glass-stoppered 
bottle, and make the mass when required. A mixture of syrup and 
water, or glycerin and water, may be used with advantage in place 
of water, as in the case of pills of aloes and mastic. 

The Official Masses. 

As stated before, these masses are usually employed as constituents 
of other pill-masses ; they are Massa Copaibae, Massa Ferri Carbonatis, 
and Massa Hydrargyri. The last named alone is of sufficiently firm 
consistence to admit of being rolled into pills which will retain their 
spherical shape without the addition of absorbents, except when 
freshly made in warm weather. 

Mass of Copaiba. This is made by mixing six parts of calcined 
magnesia, previously dampened with water, with ninety-four parts of 
copaiba, heating the mixture for one-half hour on a water-bath, and 
setting it aside until it has assumed a pilular consistence. Copaiba 
contains an acid resin capable of uniting with magnesia to form a 
solid mass, which may be looked upon as magnesium copaivate ; upon 
exposure this resin compound becomes dry and hard. Of the differ- 
ent commercial varieties, the Maracaibo copaiba is best adapted for 
making the official mass ; it is thicker than the rest, not quite transpar- 
ent, and contains less volatile oil. When mixed with ^ of its weight 
of freshly-calcined magnesia, good Maracaibo copaiba becomes heated 
and sets to a solid mass in the course of a few hours. Experience has 
taught that the previous addition of water to the magnesia materially 
facilitates the reaction. Mass of copaiba is sometimes known as 
solidified copaiba ; although it can be formed into pills, these will not 
retain their shape unless some vegetable powder has been added. 



334 PRACTICAL PHARMACY. 

Mass of Ferrous Carbonate, or Vallett's Mass, is a mixture 
of ferrous carbonate, sugar and honey. Even when very carefully 
made, so as to contain the full amount of iron salt, it is never of a 
pilular consistence, but always in the form of a rather tenacious paste. 
The Pharmacopoeia directs the formation of ferrous carbonate by mix- 
ing solutious of ferrous sulphate and sodium carbonate in the pres- 
ence of sugar, and then washing the precipitate well with sweetened 
water until the newly-formed sodium sulphate has been removed ; 
the washing is best performed by decantation in flasks having a 
narrow neck, and which can be tightly stoppered. Theoretically the 
official product should contain about 42 per cent, of ferrous carbon- 
ate, as 100 Gm. of crystallized ferrous sulphate will yield 42 Gm. 
of the carbonate, but as there is always some loss during the wash- 
ing process, the finished mass rarely contains more than 36 per cent., 
and this much only, if care has been observed to prevent oxidation 
by rigid exclusion of air. Freshly precipitated ferrous carbonate is 
greenish-gray, gradually deepening in color, and the finished mass is 
decidedly green, but should not be brown, which would indicate 
oxidation. When Vallett's mass is allowed to stand for some time, 
even in well-covered jars, it becomes dry on the surface, and assumes 
a blackish-green color. The change extends to the interior very 
slowly, being due to the gradual escape of moisture. 

Mass of Mercury, better known as Blue Mass or Blue Pill, is 
probably the most familiar of all pill-masses. In the official formula 
thirty-three parts of mercury are triturated with a mixture of three 
parts of glycerin and thirty-four parts, of honey-of-rose, until extin- 
guished, the viscid character of the vehicle enabling a rapid division 
into minute globules. When mercury is no longer visible to the 
naked eye, and the mixture has assumed a uniform brownish-gray 
appearance, five parts of powdered liquorice-root and twenty-five parts 
of powdered althsea are gradually added with constant trituration, 
until the mercury is so finely divided that if cannot be detected 
with a lens of at least ten diameters magnifying power. Blue mass 
contains 33 per cent, of metallic mercury, which probably undergoes 
slight superficial oxidation in the course of time, but is Avell protected 
by the other ingredients. In my experience the mass will be some- 
what improved in consistence if the amount of glycyrrhiza officially 
directed be doubled and the amount of althyea correspondingly 
decreased. 



CHAPTER XXIX. 

CONFECTIONS AND LOZENGES. 

Confections. 

This now almost obsolete class of medicinal preparations still 
fluids recognition in the leading pharmacopoeias, although, in this 
country, at least, they are very rarely used by physicians. At one 
time the incorporation of saline and vegetable remedial agents with 
honey or fruit-pulp was a favorite mode of medication, such being 
the invariable composition of electuaries or confections which were 
dispensed in the form of a thick semifluid mass, When made with 
honey, or with the addition of glycerin, confections will retain their 
original soft condition for a long time ; but if made with fruit-pulp, 
or sugar and water, the moisture gradually evaporates and the mass 
becomes dry and hard. All medicinal ingredients must be added in 
the form of impalpable powder, and heavy metallic salts should 
never be employed, as they are apt to sink to the bottom, and thus 
become separated. Whenever essential oils are to be incorporated 
in confections they should first be triturated thoroughly with some 
finely-powdered sugar ; narcotic extracts or other potent remedies 
should be added in the form of solution, so as to insure their 
uniform distribution throughout the soft mass. 

The U. S. Pharmacopoeia at present recognizes but two confec- 
tions, and the German Pharmacopoeia one (JElectuarium Sennce), while 
the British Pharmacopoeia still retains eight — namely, confection of 
hips, opium, pepper, roses, scammony, senna, sulphur, and turpentine. 

The Official Confections. 

Confectio Rosce. This preparation, which at one time was largely 
used as a favorite excipient for certain pill masses, possesses little or 
no medicinal virtue. It contains 8 per cent, of red rose leaves, which 
are rubbed with warm rose-water previous t© the mixture with sugar 
and honey, for the purpose of reducing the rose petals to the condi- 
tion of a soft pulp, and thus replacing freshly gathered rosebuds. 

Confectio Sennce. Confection of senna, sometimes called for under 
the name of lenitive electuary, if carefully prepared, presents an 
agreeable mild laxative preparation. If the fig, tamarind, prune, 
and purging cassia, finely bruised, be digested with the water, in a 
covered vessel, for three hours, on a boiling water-bath, and occa- 
sionally stirred with a stiff glass-rod or porcelain spatula, there will 
be no necessity to rub the pulp through a coarse hair-sieve with the 



336 PRACTICAL PHARMACY. 

hands, since a horn or porcelain spatula will answer as well, and is 
surely more desirable in every way. After the sugar has been dis- 
solved in the hot pulpy liquid, the mixture evaporated to the required 
weight and allowed to cool somewhat, the senna and oil of coriander, 
having previously been triturated with a portion of the sugar, may 
be incorporated. 

Lozenges or Troches. 

Lozenges are solid, flattened masses of round, oval, or other desir- 
able shape, not intended for mastication, but to be dissolved slowly in 
the mouth, therefore, not adapted for medicines which are expected to 
undergo disintegration in the stomach prior to any therapeutic action. 
In one or two cases the cylindrical form is preferred, as for the well- 
known liquorice lozenges and Wistar's cough lozenges. The remedial 
action of lozenges is generally designed to be purely local, either as an 
expectorant, demulcent, stimulant, sedative, astringent, or antiseptic. 

The usual base or vehicle for lozenges is sugar (that known 
among confectioners as lozenge sugar being preferred), although 
powdered extract of liquorice is also added at times, and, of late years, 
fruit paste, made from black or red currants, has been advocated for 
certain kinds of lozenges. Adhesiveness is obtained by the addition 
of tragacanth or acacia, and syrup or water (plain or aromatic) is used 
to supply the necessary moisture. All medicinal constituents, as 
well as the sugar or extract of liquorice, should be in very fine 
powder to insure a smooth paste, and potent remedies, wherever 
possible, should be added either in the form of solution or triturated 
with a small quantity of sugar before being mixed with the other 
ingredients, so as to insure uniform distribution. Tragacanth is 
preferable to acacia for making a lozenge mass, as the resulting 
paste is more tenacious ; in both cases the mucilage is to be pre- 
ferred to the powder with the subsequent addition of water, as, in 
the latter case, it is often difficult to avoid an excess of moisture, 
which retards subsequent drying. Lozenge-masses are made after the 
manner of pill-masses, except that more adhesive material is used, 
and the paste is made somewhat softer. The proportion of powdered 
tragacanth necessary for a well-made plastic mass may vary from 1 
to 3 per cent, of the total weight of the mixed powders (acacia about 
three or four times as much) ; and, in making the mass, the neces- 
sary water or syrup should be added cautiously, and the mixture 
well kneaded after each addition, so as to avoid too soft a condition, 
which readily occurs on account of the great solubility of the sugar. 
A good plan is to follow the suggestion of Hager, to reserve about 
one-fifth of the powder, and, when the remaining four-fifths have- 
been made into a plastic mass, quickly incorporate the reserve por- 
tion, which can be done without risk of the mass becoming dry 
or crumbly. For massing small quantities of material a Wedgewood 
mortar and pestle will be found quite convenient, while for large 
quantities the pill-mass mixers shown on page 310 are preferable. 



COXFECTIOXS AXD LOZEXGES. 



337 



After a suitable mass has been made it is transferred to a hard- 
wood board or a stone slab, rolled out into either a flat sheet or a 
cylinder, and divided into the requisite number of parts. When 
cylindrical lozenges are to be made, the mass is rolled out without 
dusting and divided into pieces about five-eighths of an inch in 
length, by means of a special cutter. In order to prevent the mass 
from adhering, the flat roller may be lightly rubbed with a very 
small quantity of oil of sweet almond. For flat lozenges the mass 
is conveniently rolled out into a sheet, the required thickness of 
which must be ascertained by experiment ; this is done by dividing 
the weight of the whole mass by the number of lozenges to be made, 
then weighing off as many grains of the mass as correspond to the 
quotient obtained, and forming this into a lozenge by means of a 
punch or spatula. As every well-made lozenge-board is provided 



Fig. 225. 




Showing the manner of rolling out the lozenge-mass. 

with guides and screws for regulating different thicknesses, no diffi- 
culty will be experienced in adjusting the side strips to the proper 
height, and then rolling out the mass by means of a cylindrical 
roller, as shown in Fig. 225. To prevent adhesion of the mass, the 
board may be dusted with a little starch or a mixture of starch and 
sugar. 

The lozenge-board lately designed by Wallace Procter is very 
useful and simple in construction, as shown in Fig. 226. A is a 
board of well-seasoned hard wood, 1 j- inches thick, 10 inches wide, 
and 14 inches long, planed perfectly flat, and both sides and ends made 
square and true. At each side, about 3 inches from one end, a plate 
is let in flush and tapped with a SGrew, as shown in B. On each 
side of the board a plate of brass, \\ inches wide, 14 inches long, 
and i 3 ^ of an inch thick, is fitted. Each plate has two slots crossing 

22 



338 



PRACTICAL PHARMACY. 



it diagODall y (see C) f of an inch from each edge ; these slots must 
have exactly the same slope, and the front slot should be ruled to 



Fig. 226. 



o 




Procter's lozenge-board. 



divisions of -g^ of an inch. Through one slot of each plate a 
square-shouldered screw passes, and is screwed in until it presses the 

Fig. 227. 




Harrison's lozenge-board. 



plate close to the side of the board, but still permits it to move 
easily ; through the other slot in each plate passes a set screw, which 



COXFECTIOXS AXD LOZEXGES. 



339 



euters the screw-plate before mentioned. When the plates have 
been adjusted to a given height the set screws are turned until they 
prevent motion of the plate. 

Harrison's lozenge-board (see Fig. 227), which has been known 
for some years, consists of two frames of wood, of which one moves 



Fig. 22S. 



a 



-, 






















MS 


wssm 























Harrison's lozenge-board (sectional view). 



forward and backward inside of the other in grooves cut into the 
outer frame ; the board on which the mass is rolled rests firmly on 
the inner frame, and has fastened to its bottom two bevelled strips 
corresponding to similar strips attached to the frame. By means of 



Fig. 230. 



Fig. 229. 





Fig. 231. 



Jg^e 



Plain tin lozenge-cutter. 



Tin lozenge-puuch with steel 
cutter. 



Lozenge-punch with 
spring. 



a screw the inner frame can be pushed forward, and the board thus 
forced upward (see Fig. 228). As the bevels give f of an inch rise, 
for which fifteen complete revolutions of the screw are required, each 



340 



PRACTICAL PHARMACY 



half-turn of the screw will cause a rise of -g 1 ^- of an inch; in this way 
any required thickness of the mass can be obtained. The outer frame 
is stationary, the sides projecting f of an inch above the ends, and 
serving as a support for the rolling-pin, which is also provided with 
a flange at each end to keep it in proper position. While the rolling- 
pins are usually made of wood, steel or glass rollers may also be 
used, the former being particularly desirable when heat is to be 
employed. 

The punches used for cutting lozenges are usually in the form of 
tapering cylinders made of heavy tinned-iron, and frequently pro- 
vided with sharp cutters of hardened steel, the shape of which varies 
with the fancy of the operator ; sometimes they are made with straight 
sides and fitted with a plunger, operated by a spring, for the ready 
expulsion of the lozenges. Figs. 229, 230, 231 represent some of 
the usual styles. In large manufacturing establishments ten or 
twelve cutters are frequently combined and operated as one, greatly 
expediting the work. Whenever it is desired to stamp lozenges 
with some special letter or design, this is done at the time of cutting 
them, the plunger being provided with the necessary die. 

As the preparation of lozenges has almost entirely passed out of 
the hands of the retail pharmacist, very few stores are now provided 
with suitable appliances for making them. When a small number 



Fig. 232. 




Fig. 233. 




Base for lozenge apparatus, 



Lozenge apparatus. 



of lozenges is wanted extemporaneously, a stiff mass should be made 
in order to facilitate subsequent drying; it may then be rolled out 
on a pill-machine or pill-tile, to be cut into the requisite number of 



CONFECTIONS AND LOZENGES. 341 

parts, each of which should be given a globular shape aud then flat- 
tened into a suitable disk, for which purpose the simple apparatus 
shown in Fig. 232 will be found very convenient. This consists of 
a brass or steel tube, about 2 or 3 inches long, § to f of an inch in 
diameter, and of J- or r 3 g of an inch thickness ; the bore of the tube 
must be uniform and smooth and the ends square, otherwise the 
lozenges will present an irregular appearance. A plunger accur- 
ately fitting the tube, preferably made of the same metal, is neces- 
sary ; it should be of the same length as the tube, and provided with 
a top about an inch long, exactly covering the outside diameter of 
the tube. It is desirable that both parts be nickel-plated. To shape 
the lozenges properly, the globular mass, slightly dusted with starch 
and sugar or lycopodium, is placed in the cylinder resting upon a 
metallic base, which consists of a nickel-plated piece of steel or 
brass, about 2 inches square and \ inch thick, set in a block of 
hard wood (see Fig. 233); the plunger having been inserted, it is 
struck a quick, sharp blow with a mallet, after which the cylinder is 
raised and the lozenge expelled by slightly tapping the plunger with 
the mallet. The apparatus shown on page 346, Fig. 234, may also 
be employed for shaping lozenges, although it is inferior to the 
above for compressing masses, owing to the projection of the base 
into the cylinder. 

Gelatin lozenges, variously medicated, have been in use for some 
time, more particularly in Europe. They are composed of a mixture 
of gelatin, glycerin, and water, holding the medicinal ingredients 
either in solution or simple admixture. Gelatin lozenges must be 
made with the aid of heat, and poured, in a melted condition, into 
suitable moulds ; they rapidly congeal. The base is often termed 
gly co-gelatin, and is made by macerating gelatin with water, on a 
water-bath, and then adding glycerin ; two kinds, containing different 
proportions of gelatin and glycerin, are in use. A mixture of gelatin, 
1 ounce ; orange-flower water, 2J ounces ; and glycerin, 2J ounces 
(by weight), yields the softer variety, which is very readily soluble 
in the mouth ; whereas a mixture of gelatin, 5 ounces ; orange-flower 
water, 6 ounces; and glycerin, 6 ounces (by weight), evaporated to 15 
ounces, produces a much firmer mass, dissolving more slowly, but 
probably better adapted for stock lozenges in this latitude; in the 
latter case at least twelve hours' maceration should be given the 
gelatin and water before adding the glycerin and applying heat. 

Gelatin lozenges, while admirably adapted for the exhibition of 
such substances as cocaine, boric acid, carbolic acid, etc., are totally 
unsuited for tannin, extract of rhatany, and other agents incom- 
patible with gelatin. 

Lozenges intended for immediate use do not require much drying, 
but those intended for stock must be thoroughly dried before they 
are put away in glass containers, otherwise they are liable to soften 
and adhere, and may even become mouldy. The drying is best 
effected on perforated trays, in a moderately warm room. To avoid 



342 



PRACTICAL PHARMACY. 



cracking of the edges, which will sometimes occur when lozenges are 

dried, the addition of a small quantity of glycerin to the water used 

will be found advantageous, and does not interfere with proper 
desiccation. 

The average weight of lozenges is between 10 and 20 grains, 
although in the fifteen working formulas of the Pharmacopoeia the 

weight is found to vary between 0.42 and 1.5y Gm. (6J and 24 
grains). 

The following is a list of the official lozeuges, showing the compo- 
sition and excipient used : 

Table of Official Lozenges. 

Name. Composition of each Lozenge. Excipient. 

m u . . f Tannic Acid . . . 0.060 Gm. ) a . ~ 

T T h ".- C T • ■ Sugar .... 0.650 « St ™ n S er °™& 

Acidi Tannici . | T J gacanth § Q 020 u J Flower Water. 

f Ammonium Chloride . 0.100 Gm. ] 
Ammonii J Extract of Glvcvrrhiza . 250 " flm „,„ . rr. ■. 

Chloridi . .Tragacanth V . . 0.020 « Syrup of Tolu. 

[ Sugar . . . . 0.500 " J 

I « atedm • ' • ' 0-0?0 Gm ' \ Stronger Orange 

Catechu. . .{Su ? ar canth . . . O.60O „ j F1 4er Water. 

f Prepared Chalk . . 0.250 Gm. ] 

n . Acacia . . . ' . 0.070 " I w . 

Crete. . . • j Spirit of Nutmeg . . 0.030 Cc Water ' 

[ Sugar .... 0.400 Gm J 

f Oleoresin of Cubeb . . 0.040 Gm. ] 

^ , , Oil of Sassafras . . 0.010 Cc <-, e rr. i , 

Cubebse . -{ -n, . ± ? ^^^ i • a 4>^a n r Syrup 01 lolu. 

Extract of Glvcyrrhiza . 0.2o0 Gm. j J F 

I Acacia . . . . 0.120 " J 

„ . f Z e ™ H 7 droxide ( dried ) 0-300 Gm. 1 Mudl f 

Fern .... J «a . . . . 0.010 „ J ^^ 

f Extract of Glvcyrrhiza . 0.150 Gm. ] 
ni ,. Powdered Opium . . 0.005 " 

Glycyrrhizse et Acada . 0.120 " }■ Water. 

U P n • • ' I Sugar . . . . 0.200 " | 

t Oil of Anise . . . 0.002 Cc J 

{Powdered Ipecac . . 0.020 Gm. "| 

Tragacanth . . . 0.020 " [ Svrup of Orange. 

Sugar . . . . 0.650 " J 

J Extract of Krameria . 0.060 Gm. j g r Q 

Kramer . . J Sugar ^ . . . 0.650 ^ J Flower Watei , 

Mentha- f Oil of Peppermint . 0.010 Cc \ Mucilage of 

Piperita . . \ Sugar .... 0.800 Gm. J Tragacanth. 

f Morphine Sulphate . . 0.0016 Gm. "1 

Morphinae et j Powdered Ipecac . . 0.005 " j Mucilage of 

Ipecacuanha? j Sugar . . . . 0.650 " | Tragacanth. 

L Oil of Gaultheria . . 0.002 Cc. J 



CONFECTIONS AND LOZENGES. 



343 



Name 

Potassii 
Chloratis 



Santonin 



Sodii 

Bicarbonatis 



Zingiberis 



Composition of each Lozenge. 
Potassium Chlorate . . 0.300 



Sugar 
Tragacanth 

Spirit of Lemon 

Santonin . 

Sugar 

Tragacanth 

Sodium Bicarbonate 

Sugar 

Xutmeg . 

Tincture of Ginger . 

Tragacanth 

Sugar 



1.200 
0.060 
0.010 

0.030 
1.100 
0.030 

0.200 
0.600 
0.010 

0.200 
0.040 
1.300 



Gm. 

« 
Cc. 

Gm. 

u 

Gm. 



Cc. 
Gm. 



Excipient. 



[- Water. 



Stronger Orange 
Flower Water. 



Mucilage of 
Tragacanth. 



Syrup of Ginger. 



CHAPTEE XXX. 

COMPRESSED TABLETS AND TABLET TRITURATES. 
Compressed Tablets. 

This class of remedies, closely allied to lozenges, was introduced 
about fifty years ago in England, and afterward in this country, 
under the name " compressed pills." The name, however, is erro- 
neously applied, as pills are understood to be made from a previously 
prepared plastic pill-mass. Compressed tablets have of late years 
grown greatly in favor with physicians, but it is questionable whether 
this form of administering medicines is as universally desirable as 
some manufacturers would claim ; while, in some cases, tablets appear 
more convenient than pills and powders, it would seem as though the 
prompt action of certain remedies must be considerably impaired by 
firm compression. They are lenticular-shaped disks, containing one 
or more medicinal ingredients, obtained by compressing the sub- 
stance, in the form of a granular powder, into suitable shape, by 
means of hand- or steam-power, in specially constructed apparatus. 

The composition of all compressed tablets should be such that they 
will readily undergo disintegration and solution in the stomach, hence 
they should be made with as little adhesive excipient as possible; like 
pills, they are iutended to be swallowed without previous mastication. 
When several medicinal agents are to be simultaneously exhibited in 
tablet-form it is essential, as in the case of lozenges and pill-masses, 
that they be reduced to very fine powder, in order to insure a uniform 
composition of the mixture, which is subsequently brought to a gran- 
ular condition by moistening with a suitable excipient and pressing 
the damp mass through a sieve of 16 or 20 meshes to the linear 
inch ; the granules, still damp, must be thoroughly dried before they 
are compressed, otherwise they will adhere to the sides of the moulds. 
In a few cases, when the substance to be compressed possesses no in- 
herent adhesive properties, dilute syrup is employed as au excipient, 
or a slight addition of finely-powdered sugar is made, and occasion- 
ally, although rarely, finely-powdered acacia is added in the propor- 
tion of 3 or 5 per cent, of the total weight of the powdered substance. 
As a rule, water, various mixtures of alcohol and water, or possibly 
a mixture of glycerin and water, or of glucose and water, are em- 
ployed as excipients. 

Many substances do not require any excipient at all, and can either 
be bought in the required granular condition or be easily reduced by 
grinding in a mortar or mill; to this class belong potassium chlorate, 



COMPRESSED TABLETS AXD TABLET TRITURATES. 345 

the alkali iodides, bromides, and chlorides, quinine bisulphate, etc. 
Fine powders are never adapted for compression, since the air which 
they cany with them when fed into the mould is coufined in the 
small interstices between the particles, and cannot escape upward or 
downward ; hence imperfect compression results ; moreover, fine 
powders often have a tendency to cake, when they cannot be properly 
fed into the moulds. 

AVhile some substances can be compressed quite readily, others 
present some difficulty, and, in fact, each substance or combination of 
substances requires special study and treatment. !N"o rule can be laid 
down as to the use of excipients, and experience alone will prove the 
operator's best teacher. Charcoal and substances of a similar non- 
cohesive or spongy character require the addition of about 5 per 
cent, of powdered acacia, and must be well moistened with a mixture 
of glucose and water before they can be properly granulated ; for such 
substances it is also preferable to use a Xo. 12 sieve for granulation. 
Some authorities recommend the addition of 25 per cent, of sugar in 
place of acacia ; but, although this combination would yield a more 
soluble tablet, it has been found unsatisfactory in practice. Sub- 
stances very sparingly soluble in water, such as phenacetin, acetanilid, 
salol, sulphonal, etc., are improved by the addition of a little starch, 
and alcohol will serve well to form the mass for granulations. 

If tablets, upon solution, are designed to yield effervescent draughts, 
they may be made by first preparing the corresponding granular effer- 
vescent salts (see page 366) and compressing these, or the ingredients 
upon which the effervescence depends may be granulated separately 
(preferably in granules of the same size) and then mixed thoroughly 
just before compression. Thus, if effervescent tablets of lithium 
citrate or carbonate are wanted, the lithium salt could be granulated 
with the sodium bicarbonate and a little sugar, while the tartaric acid 
and the remainder of the sugar should be mixed and separately 
granulated with alcohol ; when both granules are perfectly dry they 
may be mixed and compressed. All effervescent tablets must be 
carefully protected against moisture, in air-tight bottles. 

Whenever tinctures or fluid extracts are to be administered in 
compressed tablet form they are preferably evaporated with moderate 
heat, on a water-bath, to a syrupy consistence, before they are mixed 
with the other ingredients ; if no diluent powder has been prescribed, 
the syrupy liquid must be incorporated with a mixture of finely- 
powdered starch aud sugar, for the purpose of granulation. Solid 
extracts may be used either in the form of very fine powder or softened 
with a little alcohol, diluted alcohol, or water, as the case may be, 
then incorporated with the vehicle and granulated in the same 
manner as the syrupy liquids above mentioned. 

The preparation of compressed tablets in small quantities may be 
conveniently accomplished at the dispensing-counter, and various 
combinations readily furnished on extemporaneous prescriptions. 
The finely-powdered ingredients, having been intimately mixed and 



346 



PRACTICAL PHARMACY. 



Fra. 234. 



properly dampened, may be quickly passed through a No. 20 or No. 
30 sieve, and the granules rapidly dried by rotating them on a sheet 
of smooth paper placed in a sieve or on a perforated tray over a 
stove or other heated surface; as soon as dry the granules should be 

weighed and divided into the requisite 
number of parts, which will then be 
ready for compression. 

Different styles of compressors have 
been designed at various times to suit the 
purposes of dispensing pharmacists. (See 
Figs. 234, 235, and 236.) They are all 
fed on the same principle, and the mode 
of operating them differs but slightly. 
The cylinder, base, and piston are usually 
made of hardened steel, nickel-plated ; 
the base, which is made to project some- 
what into the cylinder, as shown in Fig. 
234, having been adjusted, the granular 
substance is carefully fed into the cylinder 
from a piece of stiff paper, the piston is 
inserted over the granules, and compres- 
sion effected either by a sharp blow from 
a wooden mallet, or by means of a lever, 
as shown in Figs. 235 and 236. When 
the tablet has been compressed it can be 
removed by lifting the cylinder from the 
base, the tablet adhering to the concave 
surface of the piston, and gently tapping 
the piston with the mallet or lever, which 
expels the tablet. The Smedley compressor (Fig. 235) is provided 
with a small receptacle, over which the cylinder and piston can be 
placed and the tablets discharged directly into it. 




Simple mould for compressed tablets. 



Fig. 235. 




The Smedley pill-compressor. 



The greater the pressure applied, the firmer will be the compres- 
sion, but, at the same time, the slower will be the disintegration of 
some compressed tablets ; hence only sufficient pressure should be 
used to cause the particles to cohere properly without crumbling 
when handled or breaking if allowed to fall. 



COMPRESSED TABLETS AND TABLET TRITURATES. 347 



Some substances show a disposition to stick in the mould, and are 
then removed with difficulty. This tendency can be overcome by the 
addition of a small quantity of purified talcum and a few drops of 
liquid petrolatum, which latter may be applied by spraying a solu- 
tion of it in ether on the granules. By thus lubricating the surfaces 
of the mould the tablet is readily discharged. In a few cases plain 
water has been found very serviceable, provided no solvent effect is 
produced on the substance to be compressed, as, for instance, with 
phenacetin, salol, naphthalene, etc. If, at any time, a compressed 
tablet should become fixed in the 
cylinder or in the concave depres- 
sion of the piston, or possibly, if 
fine powder having been inad- 
vertently used, some of it should 
have been forced between the 
piston and the sides of the cyl- 
inder, and thus fastened have the 
piston, warm water alone should 
be used to relieve the trouble ; but 
never should a sharp instrument 
be employed to loosen the adher- 
ing material, as this would be 
likely to produce rough surfaces 
or edges, thereby rendering the 
compressor unfit for use. 

For manufacturing compressed 
tablets on a large scale, special 
machinery has been constructed 
to be operated by hand- or steam- 
power. These machines can be so 
adjusted that a definite quantity of material will be automatically 
fed into the mould ; therefore, as the pressure applied is uniform, 
the resulting tablets must be of even weight and thickness. Of 
the various machines made, the Oriole Tablet Compressor (Figs. 
237 and 238) possesses some advantages which adapt it also for 
smaller operations, such as the manufacture of 50 or 100 one- 
or two-grain tablets, without the loss of material. The improve- 
ment consists in a peculiarly-constructed feeder, the shape of which 
tends to keep the material constantly at the outlet, hence every par- 
ticle of it will be discharged into the mould ; to prevent any change 
in the character of the mixture to be compressed, an ingenious stirrer 
within the feeder keeps the material in constant motion toward the 
outlet. 

In the " Oriole," as in all automatic tablet machines, the adjust- 
ment of the supply of material must be made tentatively ; the die 
or chamber, in which the granules are compressed, is situated below 
the plate, its capacity being adjusted by means of a screw which con- 
trols the depth to which the lower punch shall be allowed to drop in 




Whitall's compressed tablet machine. 



348 



PRACTICAL PHARMACY. 
Fig. 237. 



HI \ 



Oriole tablet compressor (front view) 
Fig. 238. 




Oriole tablet compressor (rear view). 



COMPRESSED TABLETS AND TABLET TRITURATES. 349 

the die. HaviDg adjusted the die approximately, the granulated ma- 
terial is allowed to be fed into it by the hopper and compressed by 
means of the upper punch situated above the plate and operated by 
the large wheel on the side; the resultiug tablet is then weighed, and, 
if necessary, the capacity of the die is increased or diminished, as the 
weight of the first tablet may iudicate. The pressure to be exerted 
upon the tablet is regulated by meaus of a long screw running per- 
pendicularly through the upper plunger and bearing upou the upper 
punch. The proper adjustment having been made, the feeder can 
supply only as much material as the die will hold, hence the automatic 
supply must be uniform and exact. All automatic tablet machines 
are so constructed that each tablet as fast as compressed is pushed 
from the mould into a receptacle suitably provided ; in the " Oriole" 
machine this is done by the hopper as it advances to feed the die. 

The dies and punches of all compressors can be had of different 
sizes, from^j to J inch or more in diameter, to accommodate tablets 
of various weights ranging from J to 30 or 40 grains ; they should be 
perfectly true and highly polished, aud must be kept scrupulously 
clean and dry. If not nickel-plated, they should be coated with a 
little petrolatum, when not in use, to prevent rusting. 

Tablet Triturates. 

This class of preparations was introduced, in 1878, by Dr. R. M. 
Fuller, of New York, no doubt, with a view of administering small 
quantities of potent remedies in convenient, palatable, and readily- 
soluble form. Since then some manufacturing firms have made 
strong efforts to induce physicians to resort to this method of medi- 
cation for the purposes of office dispensing. That the growth of 
homoeopathic patronage has largely aided the introduction and use of 
tablet triturates cannot be denied. 

Tablet triturates are made by triturating the active ingredient with 
either plain sugar of milk or a mixture of sugar of milk and ordinary 
or cane-sugar (usually in the proportion of 4 or 5 parts of the former 
to 1 part of the latter), and then forming the mixed powders into a 
paste with alcohol, alcohol aud water, alcohol and syrup, or water 
alone, which paste is pressed into tablets in appropriate moulds. 
The composition of the liquid excipient to be employed wdl vary 
greatly according to the diluent used, the nature of the medicinal 
ingredients operated upon, and also the quantity to be present in each 
tablet, the aim being to produce a partial softness in the mixture 
which will enable the particles to adhere together in the form of a 
firm, pasty mass. When simply milk-sugar is used as a diluent, 
water alone will answer as the excipient in most cases, but when a 
mixture of milk-sugar and cane-sugar is used, a strougly alcoholic 
liquid excipient is necessary, on account of the ready solubility of 
cane-sugar in water, the proportion of alcohol being increased as the 
quantity of cane-sugar is augmented. For most operations at the 



350 PRACTICAL PHARMACY. 

dispensing counter, where no special facilities for rapid drying are at 
hand, a mixture of 5 parts of milk-sugar aud 1 part of cane-sugar, 
together with an excipient composed of 15 volumes of alcohol and 1 
volume of water, will perhaps prove most desirable, as the greater 
volatility of the alcohol insures more rapid drying of the tablets. 

It is essential that the sugar be in very fine powder, in order to 
yield a smooth paste and perfect tablets ; and, if the mixture be 
passed through a No. 120 sieve, before making the paste, the results 
will be all the better. A few cases will occur in which sugar and 
other organic matter is inadmissible as a diluent, owing to chemical 
changes likely to occur; as, for instance, potassium permanganate, 
silver nitrate, etc. ; finely powdered kaolin, or pipe-clay, should then 
be used with water as an excipient. 

Tinctures and fluid extracts, unless strongly alcoholic, are made 
into tablet triturates with more or less difficulty, according to the 
amount of fluid to be represented in each tablet, and may require 
evaporation to dryness with a portion of the sugar, so as to be sub- 
sequently reduced to fine powder, prior to converting into a suitable 
paste. The presence of glycerin, especially if in large proportion, is 
objectionable, since it keeps the extractive matter soft aud prevents 
proper drying of the tablets. In some instauces it will suffice to 
concentrate the fluid by evaporation and use it, in place of excipient, 
for moistening the mixed powders ; but this plan can only be followed 
when the proportion of fluid ordered is small or when it has been 
made with a strongly alcoholic menstruum. Solid extracts can be 
introduced only in small proportions, and may then be incorporated 
as indicated under compressed tablets ; more than one-fourth or one- 
third of the total weight of the tablet triturate is not advisable. In 
such cases, and also in the case of tablets to contain various amounts 
of tinctures or fluid extracts made with hydro-alcoholic menstrua, a 
mixture of milk-sugar and starch in varying proportions will be 
found the best diluent. Substances of a volatile or deliquescent 
character, or such as are readily oxidized upon exposure to air, are 
wholly unfit for tablet triturates ; hence camphor, creosote, calcium 
sulphide, arsenic iodide aud bromide, potassium citrate, scale salts of 
iron, phosphorus and the like should never be dispensed in this form. 

Automatic machines for making tablet triturates have not yet been 
constructed, and the apparatus generally used, whether for small 
quantities at the dispensing counter or in the manufacture of tens of 
thousands in the laboratory, cousists of two plates, as shown in Fig. 
239. The plates, although sometimes constructed of metal, are 
preferably made of hard rubber, the upper one being perforated and 
the low r er provided with a corresponding number of pegs, which 
fit accurately iuto the perforations of the upper plate. In order to 
insure the exact position of the pegs when the upper plate is brought 
down over them, two guide-pins are fastened to the lower plate, one 
near each side ; these extend above the pegs and enter two corre- 
sponding holes in the upper plate. As a rule, the plate moulds are 



COMPRESSED TABLETS AND TABLET TRITURATES. 351 

made to prepare 50 or 100 tablet triturates at one time, although 
some are provided with 200 or more perforations, and a few with 
only 25 ; the perforations vary from one-eighth to three-eighths of 
an inch in diameter. Since the plates can also be had of different 
thicknesses, the weight of the tablets made may range from one-half 
to five grains or more, according to the density of the mass. 

Fig. 239. 






JHptajlllc 




Hard-rubber mould for tablet triturates. 



When a suitable paste has been made the perforated plate is placed 
upon a level surface, preferably a thick glass plate, and, by means of 
a horn or rubber spatula, the mass is forced into the holes so as to 
fill these completely, any excess of material being removed with the 
spatula ; the plate is then reversed and, if necessary, more of the 
mass is forced into the holes until they are completely filled and both 
sides present a smooth, solid surface. After the required number of 
holes have been filled, the upper plate is carefully brought down over 
the lower one with the marks or numbers at the ends of the two 
corresponding and, by the aid of the guide-pins, the pegs are pressed 
into the corresponding holes and the tablets thus forced out, remain- 
ing on the ends of the pegs ; after a few moments they may be re- 
moved, either by inclining and tapping the plate or by carefully 
brushing them into a suitable receptacle, preferably a bolting-cloth 
sieve. The tablets should then be dried either by exposure to the 
ordinary room temperature, protecting them from dust, in closets 
supplied with circulating warm air, or in small quantities on a per- 
forated tray near a stove or register, as the nature of the medicinal 
ingredients may permit. 

Some manufacturers use an apparatus somewhat differently con- 
structed, as shown in Fig. 240. The two plates are held in frames 
hinged together and so arranged thai the peg-glate can be brought 
down accurately over the perforated plate carrying the tablets, and 



352 PRACTICAL PHARMACY. 

by pressing the pegs down through the perforations the tablets are 
made to drop out upon a sheet of paper placed underneath for their 
reception. The exact amount of mass capable of being forced into 
the holes depends largely upon the pressure exerted by the operator, 
and varies with nearly every person ; besides, different combinations 
moulded by the same person, being of different specific gravities and 
compactness, will give different results; the weight of a certain tablet 

Fig. 240. 




Colton's tablet triturate mould. 

having been ascertained, a memorandum should be made of the 
details regarding combination, diluent, and excipient, for future 
reference. 

Every formula for new tablet triturates must be determined tenta- 
tively in order to ascertain the exact amount of sugar of milk or 
other diluent required. The simplest plan is to weigh off enough of 
the active ingredients to make a given number of tablets (say 25 or 
50) ; mix this with a quantity of diluent known to be insufficient, 
moisten with the necessary excipient, and press the mass into the 
holes of the plate intended to be used. Then moisten more of the 
same diluent with the excipient, and, with this paste, fill the holes 
remaining unfilled from the first operation ; smooth off both sides of 
the tablets, place on the ejecting-pegs and force the tablets out. For 
larger operations the tablets should then be thoroughly dried and 
weighed, the weight of the dry tablets less the weight of active ingre- 
dients used representing the weight of the diluent required to make 
the given number of tablets. In small operations, particularly those 
of the dispensing counter, the drying may be omitted, and, instead, 



COMPRESSED TABLETS AND TABLET TRITURATES. 353 

an extra number of tablets (4 or 5) made out of the plain diluent, 
added to the number first obtained, before the whole is thoroughly 
mixed in a mortar ; this extra material is necessary because the first 
tablets, when worked up again in the mortar, generally form a more 
compact mass, and hence would prove insufficient for refilling the 
required number of perforations. 

Tablet triturates are, beyond doubt, far more readily disintegrated 
than compressed tablets, but the latter form has a larger range of 
applicability, owing to the many variations in quantity and composi- 
tion ; tablet triturates above 5 grains in weight become inconveniently 
bulky, and, being flat on both sides, are less readily swallowed than 
even larger compressed tablets of lenticular shape. 

Hard-rubber moulds require considerable care in cleaning and in 
storing them when not in use, in order to preserve the original perfect 
shape. They should never be exposed to heat, either by using hot 
water for washing or dry heat for drying them, as the moulds are 
thereby warped and the accurate adjustment of the pegs and perfora- 
tions is destroyed ; when thus warped, the moulds can only be used 
with great difficulty, and soon become worthless. A narrow, stiff 
paint-brush will be found very serviceable in cleaning the moulds, 
and water at the ordinary temperature should be used for washiug 
the plates ; sometimes alcohol, or even acids, may be necessary to 
remove material tenaciously adhering to the moulds, but never 
should a sharp instrument be used in the perforations or on the pegs, 
as the smooth surfaces are likely to be scratched thereby. After the 
plates have been carefully cleansed and rinsed with cold water they 
should be dried with a soft towel, the water remaining between the 
pegs being readily shaken out; w T hen dry, the perforated plate should 
be placed in proper position on the peg-plate, and the whole laid aside 
on a level, solid surface, away from heat. 

Hypodermic Tablets are simply tablet triturates intended for the 
convenient preparation of solutions for subcutaneous injection. Since 
they contain definite quantities of the active agents, they are admirably 
adapted for physicians' use at the bedside, and are very extensively 
employed. As a rule, pure sugar of milk or pure cane-sugar is used 
as the vehicle, although sodium sulphate has also been employed by 
some manufacturers. 

Tablet Saturates differ from tablet triturates only in the manner of 
introducing the medicinal agents. They are made by first preparing 
plain sugar of milk tablets, in the moulds already described, and 
having placed the tablets, when dry, on a glass plate, the desired 
quantity of tincture, fluid extract, or solution is dropped upon each 
tablet individually from a pipette. A glass cover is then placed over 
the tablets and the fluid allowed to saturate them uniformly, after 
which they are dried in a current of warm air. 



23 



CHAPTER XXXI 



POWDEES. 



Fig. 241. 



In addition to what has already been said about pulverization, in 
the chapter on Mechanical Subdivision of Drugs, there remains yet 
to be considered the administration of medicines in powder form, 
which, presenting certain advantages, is still largely employed by 
physicians. The powder form is a most eouveuient method of giv- 
ing medicines in the case of very small children and persons who are 
unable to swallow pills, as well as where the fluid form is unavail- 
able for any reason. It is true, many substances are not suited for 
administration in powder form, particularly bulky vegetable pow- 
ders, deliquescent salts, and such as contain large quantities of water 
of crystallization, as sodium phosphate or sulphate, etc.; but while 
the fluid form of medicine is probably to be preferred in the majority 
of cases, the bitter or nauseous taste of some substances becomes more 
marked in solution than in the dry state. Among the substances 
best adapted for dispensing in powder form are insoluble chemicals, 

such as calomel, bismuth salts, sulphurated 
antimony, some salts of the alkaloids, and 
vegetable drugs given in small doses, such 
as ipecac, opium, and catechu. Physicians 
frequently direct their patients to dissolve 
or mix the powder in water, and, in such 
cases, the powder form is preferred on ac- 
count of convenience or for reasons of econ- 
omy. 

Powders, as a rule, are composed of two 
or more substances ; to insure an intimate 
and uniform mixture they must be tritu- 
rated in a mortar, preferably made of por- 
celain, of the shape shown in Fig. 241, this 
style presenting a sufficiently broad surface 
at the base, whilst its curved sides prevent 
the ejection of material during trituration. It is assumed that, in 
the majority of cases, the individual ingredients are already in the 
state of very fine powder, and, therefore, only require thorough mix- 
ing, which is best accomplished by trituration with light pressure 
only, so as to avoid caking and sticking to the sides of the mortar; 
the contents of the vessel should also occasionally be scraped down 
from the pestle and sides of the mortar, if necessary, as this aids more 
perfect admixture. Whenever substances which are themselves iu 




Porcelain powder-mortar 
(sectional view). 



POWDERS. 355 

a coarsely powdered or granular condition, are ordered in a powdered 
mixture, they must be reduced to a very fine powder by themselves, 
no attempt being made to reduce them in the mixture. 

A few general rules will serve for guidance in the preparation of 
mixed powders. Whenever sugar is one of the ingredients it should 
be of the kind known as bolted or lozenge sugar. When small 
quantities of potent or other substances are to be dispensed in pow- 
ders, they should first be well triturated with a portion of the diluent, 
and, finally, incorporated with the remainder of the more bulky 
powders; or, if no diluent has been ordered, they should be tritu- 
rated with a small quantity of sugar of milk, to insure their more 
uniform distribution in the mixture. The proper plan is to place 
about 5 grains of sugar of milk in the mortar, add the active ingre- 
dient, and then triturate thoroughly, as, by this means, more accur- 
ate subdivision is effected, and none of the active material is likely 
to adhere to the sides of the mortar. Soft extracts and essential 
oils must be treated in the same manner. 

Whenever physicians prescribe quantities which cannot be weighed 
conveniently, such as \, ^, -^T' or A °^ a g ram ? an d metric weights 
less than 10 milligrammes, the plan of preparing a dilution of the 
substance with sugar of milk, by trituration, in such proportions 
that a weighable amount of the mixture shall represent the desired 
quantity of active ingredient, as already indicated on page 309, 
should invariably be followed, as by this method accuracy of 
division is best obtained. 

Certain substances of a crystalline structure — notably also those of 
a resinous character — have a tendency to become electrical by fric- 
tion, particularly if pressure be employed ; such bodies are said to be 
idioelectric, and must be triturated lightly, or, if pressure is necessary 
to reduce them to fine powder, they must be sprinkled with a little 
alcohol, whereby the trouble is obviated, or the powder, which ad- 
heres firmly to the mortar and pestle, and is apt to fly off in all 
directions if scraped with a spatula, must be set aside for awhile 
until the electric condition has disappeared. To this class belong 
common pine resin, and the resins of guaiacum, jalap, and seam- 
mony, also quinine alkaloid, acetanilid, salol, phenacetin, and 
others. The removal of these in fine powder form from the mortar 
is attended with more or less difficulty, unless previously slightly 
dampened. 

When substances which differ materially in specific gravity are to 
be mixed in powder form — as, for instance, bismuth subnitrate with 
magnesia, sodium bicarbonate with charcoal, or zinc oxide with lyco- 
podium — the best plan is to place the heavy substance in the mortar 
and incorporate the lighter body gradually by adding small portions 
at a time. Calcined magnesia and charcoal are aiso more readily 
mixed if the charcoal be gradually added to the magnesia with very 
light trituration ; only in this manner can a powder of uniform 
appearance be obtained. Whenever large quantities of these pow- 



356 



PRACTICAL PHARMACY. 



clers are to be mixed, perfect blending may be achieved by shaking 
them together in a bottle for some time, aud then passing the mixture 
repeatedly through a bolting-cloth sieve. 

Since some substances when triturated together cause chemical 
decomposition, attended in a few cases also with explosiou, consider- 
able care must be observed in mixing them ; the offending ingredient 
should be reduced to line powder by itself, and then cautiously 
mixed on paper with the other powders. Such conditions arise 
when potassium chlorate or permanganate is to be mixed with or- 
ganic substances, as sugar, starch, tannin, gum-arabic, and also sul- 
phur and sulphides, or when lead acetate aud zinc sulphate or borax 
and alum are triturated together. 

Powders, whether simple or compound, intended for external 
application, by dusting or insufflation, must be passed through a 
fine bolting-cloth sieve, and should not then be triturated again 
before they are dispensed. 

In the majority of cases medicines prescribed in powder form are 
dispensed in divided doses ; although absolutely accurate division 
can only be obtained by weighing, this plan is rarely followed, since 
practice will soon enable one to omit this tedious method. Usually 
the operator divides the mixed powder by the eye, either directly on 
the powder papers or by shaping the powder into a rectangle on a 
graduated tile, and dividing this into the requisite number of parts ; 
an experienced dispenser is able to make quite accurate divisions from 
the mortar direct to the paper. 

To facilitate the division of doses at the dispensing counter a very 
neat powder-divider was designed, some years ago, by J. C. Michael, 
a former pharmacist ; it is shown in Fig. 2 12. The apparatus con- 

FlG. 242. 




Michael's powder-divider. 



sists of a cup with base attached, a set of three dividers, with 8, 
10, and 12 wings respectively (one of which is shown in the illus- 
tration), and a cap with sliding door. It is operated as follows : 
The thoroughly mixed powder is placed in the metallic cup, B, and, 



POWDERS. 357 

after shaking down so as to obtain a level surface, the metallic 
divider, D, is slipped over the rod, A, and allowed to work its way 
slowly down to the bottom of the cup ; by slight manipulation, such 
as gently rotating the divider, the powder will be divided into as 
many equal parts as wings are attached to the divider. The cap, E, 
which fits snugly over the projecting wings of the dividers, aud is 
held in position by means of a central pin, is next attached, and, the 
cup having been inverted, the rod, A, is removed by turning the 
base, C, held by a bayonet-joint, and withdrawing the rod from the 
centre of the divider. The powder will now be found transferred 
to the cap, but divided, as before, since the wings of the divider 
extend beyond the rim of the cup to the full depth of the cap ; by 
bringing the apparatus over the centre of the paper one portion can 
be deposited at a time by pulling back the slide, F, and allowing the 
powder to fall upon the paper. It is, of course, important, when 
placing the cap on the cup, so to adjust it that the edges of the open- 
ing be on a line with two of the wings, which is best done with the 
slide open. By carrying the apparatus from paper to paper and 
rotating the divider, each succeeding section can be emptied, aud 
thus rapid division of the mixture be effected. The whole apparatus 
is nickel-plated, which protects it against rust. Very accurate work 
can be done with this apparatus, and the necessary experience for 
rapid manipulation is easily acquired. 

Another convenient device for those who do not wish to entrust 
division of powders to the eye is the Diamond Powder-divider. 
This consists of a nickel-plated, shallow, metal trough, closed at 
one end and graduated on both sides ; the powder having been in- 
troduced, a hard-rubber plug is inserted at the open end and pushed 
up to the graduation indicating the number of divisions to be made. 
After levelling the surface of the pow T der by means of an accompany- 
ing flat bar, with handle attached aud exactly fitting into the trough, 
the rubber plug is removed and a quantity of the material, equiva- 
lent to one dose, as indicated by the divisions of the graduated sides, 
is transferred to paper by the aid of a spatula of the same width as 
the interior of the trough. The dimensions of the trough are 9 inches 
in length, 1 inch in width, and f of an inch in depth. 

For enclosing the divided doses of powder, either well calendered 
or parchment paper may be used ; the latter is now preferred by 
many pharmacists, as it offers a protection against the moisture of 
the air. Even those who use glazed white paper will find either 
parchment or waxed paper necessary for volatile or hygroscopic 
substances. Powder papers should be folded uniformly, hence it 
will be fouud advantageous to keep in stock a supply of the various 
sizes already creased. This is readily done by folding the paper 
over a piece of stiff metal of suitable size, with rounded edges to 
prevent cutting, in such a manner that a narrow margin, about J- 
inch wide, is made on one of the long sides ; the straight edge hav- 
ing been brought up against the crease of the margin, both ends are 



358 PRACTICAL PHARMACY. 

folded back to about the centre of the piece of metal and firmly 
pressed down with a horn spatula. The two sides are now folded 
over the edges of the metal plate and also firmly pressed, after which 
the creases are all opened and the plate is removed. Such creased 
powder papers not only insure absolute uniformity in size and shape, 
but have also been found very convenient in economizing time at the 
prescription counter. Some pharmacists prefer to fold each paper 
containing the powder over a powder box or specially constructed 
adjustable powder-folder. The habit of flattening the powder within 
the paper by pressing over it with a spatula is a bad one, and should 
never be followed, as it is apt to cause the powder to cake, and often 
interferes with its proper administration in liquids. To prevent any 
of the material from leaving the paper, one of sufficiently large size 
should be used, that the creases where the sides have been folded 
over may be pressed down with a spatula ; this effectually prevents 
leakage. 

A small number of powders in paper (two or three) are usually 
dispensed in an envelope, while the regular oblong powder boxes are 
used for larger numbers. When not divided into doses the powder 
is dispensed either in round paper boxes (never in paper, unless in- 
tended for use at one time) or in wide-mouth bottles; the latter 
method is necessary if the ingredients are apt to attract moisture or 
if very volatile substauces are present, and will also be found con- 
venient for travelling purposes. When bottles are used, a piece of 
glazed paper should be inserted between the neck of the bottle and 
the cork, to prevent particles of the latter from falling into the 
powder. 

While, as a rule, medicines in powder form are administered to 
the patient either dry on the tongue, or in solution, or mixture with 
a small quantity of water, physicians frequently direct them to be 
enclosed in capsules or wafers, with the view of disguising the taste. 
The filling of definite quantities of a powder into capsules is rather 
troublesome, on account of the small orifice of the latter, and to 
facilitate the operation recourse is had to a little device especially 
designed for that purpose. Small blocks of hard wood are provided 
with twelve or twenty-four sockets of such depth that the capsules, 
when placed therein, shall project about one-third above the edge; 
another piece of wood, with perforations corresponding to the sockets, 
is placed over the lower block, after the capsules have been inserted, 
and then, by means of a suitable funnel (of hard rubber or metal), 
the powder is transferred to the capsules and somewhat compressed 
with a plunger exactly fitting the throat of the funnel and the cap- 
sule. After all the capsules have been filled the upper perforated 
block is removed and the cover slipped over the projecting ends of 
each capsule. For the various sizes of capsules different blocks and 
funnels are required. In Figs. 243 and 244 are shown the blocks 
and a suitable funnel; the latter has a wide rim flattened on one side 
and a short tube, whereby the powder is more conveniently fed into 



POWDERS. 



359 



the capsules. The Acme Capsule-filler (Fig. 245) is somewhat 
different in construction, but is operated in a similar manner. 



Fig. 243. 




Fig. 244. 



Hard-wood blocks for supporting empty capsules while being filled. 

The use of wafers is not so much iu vogue iu this country ^.as in 
Europe, but is, in many respects, preferable to capsules; less com- 
pression of the material is necessary, 
and the envelope, made of rice-flour, 
is more readily disintegrated in the 
stomach. Sometimes small square 
or circular sheets of wafer paper are 
Ordered, and the patient is directed 
to enclose each dose as wanted ; this 
is done by dipping the wafer into 
cold water, whereby it is rendered 
flaccid ; it is then removed with a 
spoon, the powder placed in the cen- 
tre, and, the edges having been 
folded over, it is swallowed with 
a draught of water. 

The small round wafers known 
as cachets are intended to be filled and sealed by the pharmacists. 
Various appliances have been proposed, of which that extensively 
used in Europe in connection with Mohrstadt's cachets is decidedly 
the most desirable, as it is simple iu construction and quickly oper- 
ated ; the device is sold iu this country by J. M. Grosvenor & Co., 
of Boston, as the "Konseal" Filling and Closing Apparatus, and is 
fully illustrated and described farther on. The use of the word 
"Konseal" in place of cachets of' wafers does not strike one as par- 
ticularly appropriate, and is to be regretted. The "Konseals," or 




Davenport's funnel and plunger for 
filling capsules. 



360 



PRACTICAL PHARMACY. 



cachets, are concave disks made of rice-flour and water ; they are of 
convenient form, perfectly digestible, keep permanently for years, and 



Fig. 245. 




Acrne capsule-filler. 



are prepared in six sizes, as shown in Fig. 246, varying in capacity 
from 1 to 18 or 20 grains of dry powder. 



Fig. 246. 




Konseals " or rice-flour cachets. 



The "Konseal" Filling and Closing Apparatus consists of three 
nickeled plates suitably hinged together (see Fig. 247); the centre 
plate, B, is provided with 36 concave depressions, to suit the different 



POWDERS. 



361 



sizes of wafers, and the two other plates (A and C) are perforated 
iu a manner to correspond exactly to the depressions in B. The 



Fig. 2-17. 



o o o o o o° o 

oooobb 

oooooo 




Sooooo 
poooog 

The "Konseal" tilling and closing apparatus. 

wafers are first pressed into the spaces of A and B adapted for the 
particular size selected ; one of the short funnels accompanying the 

Fig. 248. 




apparatus having been inserted into the proper perforation of plate 
C, the latter is folded over on to plate B, as shown in Fig. 248. The 
powders are next poured into the wafers, as shown in Fig. 249, and, 
if necessary, owing to large bulk, are slightly compressed with the 
thimble furnished for the purpose; small quantities of the powder 



362 



PRACTICAL PHARMACY 



can be conveniently fed into the wafers without the use of funnel or 
thimble. When the required number of wafers has been filled plate 
C is turned back from plate B, and the damping roller (not too wet) 



Fig. 249. 




passed over the wafers in plate A, as shown in Fig. 250, whereby 
the edges of the wafers are sufficiently moistened to cause them to 
adhere closely to the other wafers when plate A is closed clown over 
plate B with a little pressure. Finally, on opening the apparatus, 



Fig. 250. 




the sealed wafers will be found adhering to plate A, and can be easily 
pushed out by the fingers or with the thimbles. 

When powders are^to be dispensed either in capsules or waters it 
will, of course, be necessary first to make the required number ot 



POWDERS. 



363 



divisions on paper, either by weighiug or measuring with the eve ; 
in Europe a graduated glass tube with hard-rubber piston is said to 
be used for the same purpose. 

The Pharmacopoeia furnishes formulas for the preparation of nine 
compound powders, but directs the division into doses in only one 
case. The following is a list of the official powders and their com- 
position : 

Compound Powders of the U. S. Pharmacopoeia. 



Name. 
Pulvis : 

Antimonialis . 
(James' Powder). 



Aromaticus 



Cretan Compositus 



Effervescens Compositus 
(Seidlitz Powder). 



Glycyrrhiza? Compositus 



Ipecacuanha? et Opii . . 
(Dover's Powder). 

Jalapse Compositus . . 

Morphinse Compositus . 
(Tully's Powder). 



Ehei Compositus . 



Composition. 

Antimony Oxide . 
Precipitated Calcium Phosphate 
Ceylon Cinnamon . " . 

Ginger . . . . . . 

Cardamom (deprived of capsules] 
Xutnieg .... 

Prepared Chalk . 

Acacia ..... 

Sugar . . . . 

Sodium Bicarbonate 
Potassium and Sodium Tartrate 
Tartaric Acid 

Senna 

Glycyrrhiza .... 

AVashed Sulphur . 

Oil of Fennel 

Sugar ..... 

Ipecac ..... 

Opium 

Sugar of milk 

Jalap ..... 
Potassium Bitartrate . 
Morphine Sulphate 
Camphor .... 
Glycyrrhiza .... 
Precipitated Calcium Carbonate 
Rhubarb .... 
Magnesia .... 
Ginger ..... 



33 Gra. 

67 " 

35 Gm. 

35 " 

15 " 

15 " 

30 Gm. 

20 " 

50 " 
2.583-f 
7.749^ 
2 250 
180 Gm. 
236 " 

80 " 

4 " 

500 " 

10 Gm. 

10 " 

80 " 

35 Gm. 

65 " 
1 Gm. 

19 " 

20 " 
20 " 
25 Gm. 
65 " 
10 " 



Special Remarks. 



In the case of autimonial powder, compound chalk powder, and 
compound jalap powder, the ingredients being already in a state of 
fine powder, simple admixture with light trituration is necessary. 

Pulvis Aromaticus. Cardamom, deprived of the capsules, are 
directed, because the latter are inert and cannot be reduced to fine 
powder ; the crushed seed and coarsely powdered nutmeg (best ob- 
tained by grating) can readily be brought to a state of fine powder 
by trituration with about one-half of the cinnamon, using at the same 
time slight pressure. 

Pulvis Effervescens Compositus. The so-called " Seidlitz mixture" 



364 PRACTICAL PHARMACY. 

of commerce is not always of the composition prescribed by the Phar- 
macopoeia ; hence it is better to make it, as wanted, by mixing 1 
part of sodium bicarbonate with 3 parts of Eochelle salt. The alka- 
line mixture is usually put up in blue papers and the acid powder in 
white paper. The small wooden measures intended for rapid divi- 
sion of the powders are, as a rule, not uniform ; moreover, the quan- 
tity of material that can be compressed into these measures varies 
considerably with the condition of the atmosphere, which renders 
them unreliable ; hence, the prescribed quantities should be weighed 
for each paper, being 10.333 -f- Gm. (160 grains) of Seidlitz mix- 
ture and 2.25 Gm. (35 grains) of tartaric acid. The powders should 
be protected against dampness, and it will be found advantageous to 
dispense the acid in parchment paper. 

Pulvis Glycyrrhizce Compositus. By triturating the oil of fennel 
with a part of the sugar, before adding the other ingredients, its dis- 
tribution in the powder is greatly facilitated. The use of oil in 
place of powdered fennel is advantageous, as the finished mixture 
can then readily be passed through a No. 80 sieve, and the finer the 
powder the better it is ; moreover, the product will not assume by 
age that disagreeable odor which has been observed when the pow- 
dered seed is used. 

Pulvis Ipeeacuanhce et Opii. The Pharmacopoeia directs sugar 
of milk to be used in rather coarse powder, so that the fragments of 
crystals, being very hard, may serve to grind the vegetable powders 
to an impalpable condition during the necessarily prolonged tritura- 
tion. Since the finished product contains 10 per cent, each of ipecac 
and opium, an average adult dose, 0.648 Gm. (10 grains), of the 
powder, will represent 0.0648 Gm. (1 grain) of each active ingredi- 
ent. Dover's powder is a favorite diaphoretic. 

Pulvis Morphince Compositus. The value of Tully's powder resides 
in the camphor and morphine present, the liquorice and precipitated 
chalk serving simply as diluents. In order to secure the camphor 
in very fine division it must be triturated with a little alcohol and 
at once mixed with the diluents, the morphine being incorporated by 
adding to it the other mixed powders in small quantities at a time. 
The official formula would look better if 20 instead of 19 Gm. of 
camphor had been directed, on account of the more accurate division 
of doses. Each gramme of the finished product represents 0.0166 + 
Gm. of morphine and 0.313 + Gm. of camphor, or 10 grains equal 
^ grain of the former and about 3 grains of the latter. Owing to 
the volatile nature of the camphor the powder should always be dis- 
pensed in paraffin or parchment paper. 

Pulvis Rhei Compositus. The best plan for thoroughly blending 
the magnesia with the rhubarb and ginger will be to mix the last- 
named two powders first, then add the magnesia, in small quantities 
at a time, triturating without pressure, and, finally, pass the whole 
mixture through a bolting-cloth sieve. 



POWDERS. 365 

Triturations. 

Under this head the Pharmacopoeia recognizes mixtures of reme- 
dial ageuts and sugar of milk, in the form of a very fine powder, 
made in such proportions that each gramme of the mixture shall 
contain 0.100 Gm. of the active ingredient, or 1 grain represent y 1 ^ 
of a grain. The general official directions for making triturations 
are to mix the substance in a mortar, with an equal weight of sugar 
of milk, both in moderately fine powder, and then to triturate thor- 
oughly together, adding fresh portions of sugar of milk from time to 
time, until 9 parts of the latter shall have been mixed with 1 part 
of the substance, and the whole reduced, to a very fine powder. The 
advantage of using moderately fine powder in the beginning consists 
in the more intimate admixture of the ingredients brought about by 
the prolonged trituration necessary for reduction to fine powder. 

But one trituration is officially designated — namely, " Trituration 
of Elaterin;" this is a mixture of 10 Gm. of elaterin and 90 Gm. of 
sugar of milk, made according to the general directions given above. 

Oil-sugars. 

Powders of this class are chiefly used as correctives or flavoring 
agents, and are prescribed by physicians under the name Oleosacchara 
or Elseosacchara. These are extensively employed in Europe, par- 
ticularly in Germany, but are not recognized in our Pharmacopoeia. 

The National Formulary gives general directions for preparing 
them, which are practically identical with those of the official Ger- 
man code. Oil-sugars are composed of powdered cane-sugar and 
volatile oil only, each drachm of the former requiring the addition 
of two drops of the latter, the two being thoroughly mixed by 
trituration ; they should be freshly made when wanted. When 
prescribed, the particular kind is designated by specifying the name 
of the oil to be used — thus, oleosaccharum or elseosaccharum anisi, 
menthse piperita?, foeniculi, limonis, etc., meaning oil-sugar of anise, 
peppermint, fennel, lemon, etc. 



CHAPTEE XXXII. 

GRANULAR EFFERVESCENT SALTS. 

The administration of remedial agents in the form of effervescent 
draughts has become quite popular during the past ten or fifteen 
years, and, as the solutions are only agreeable when freshly made, it 
is necessary to have the remedies in convenient form for extem- 
poraneous preparation of the draught. Such a form is presented by 
the granular effervescent salts of the market. While the Pharma- 
copoeia recognizes but four preparations of this class, a very large 
number is offered by manufacturers, and, as they are easily made, 
without elaborate apparatus and appliances, their preparation is within 
the reach of all pharmacists. The combination consists of the active 
medicinal ingredients, the effervescent agents, and frequently sugar, 
to improve the taste. As a base for producing the effervescent 
draught, sodium bicarbonate, with citric or tartaric acid, or a mixture 
of the two acids, is employed. Effervescent granules made with citric 
acid are preferable to those made with tartaric acid, and will keep 
better, since they are much firmer ; as a rule, a mixture of the two 
acids is used. All ingredients must be dry and mixed in the form 
of fine powders. The method of granulating the mixture will vary 
with different operators; while for small quantities, such as the phar- 
macist is likely to handle, dampening of the powder with 95 per 
cent, alcohol and then rubbing the paste through a sieve offers the 
most convenient plan, large manufacturers subject the mixed powders 
to a temperature sufficiently high to fuse some of the constituents 
and thus obtain the necessary adhesiveness. 

If it is preferred to make granular effervescent salts by heat, as 
recommended in the British Pharmacopoeia, the well-mixed powders 
should be placed in a pan or dish, which has previously been heated 
to the desired temperature, and the heat then be continued until semi- 
fusion has just begun, when the pasty mass must be quickly trans- 
ferred to the proper sieve for granulation, after which the granules 
are at once transferred to the drying closet. Unless the pan be prop- 
erly heated before the powder is placed therein, the material is likely 
to dry out before it undergoes semi-fusion. 

Whenever sugar is present in the mixture to be granulated, care 
must be observed in the application of heat, to avoid a yellowish 
coloration of the granules ; moreover, the sodium bicarbonate is likely 
to loose carbon dioxide if heated beyond 72° C. (161.6° F.), thus 
rendering the preparation deficient in effervescent properties. If 
alcohol be used to make a pasty mass of the well-mixed powders, 



GRANULAR EFFERVESCES! SALTS. 367 

these difficulties are avoided, since a temperature uot above 65° C. 
(149° F.) will be found quite sufficient for drying the damp granules; 
the stronger the alcohol used, and the stiffer the paste made, the better 
will be the granular condition of the salt, especially if the subsequent 
drying can be conducted in drying-closets kept at a constant tem- 
perature. 

All the required ingredients for effervescent granules must be used 
in fine powder and thoroughly mixed before an attempt at granula- 
tion is made; trituration in a mortar is not desirable, since the re- 
sulting pressure is likely to cause reaction between the sodium bicar- 
bonate and acid, hence intimate admixture is best effected by passing 
the mingled pow 7 ders repeatedly through a sieve (preferably No. 50). 
It will also be found advantageous to mix the sodium bicarbonate 
thoroughly with the sugar (if the latter is to be used) before adding 
the acid. Strong alcohol only should be used (not below 7 94 or 95 
per cent, by volume) for making a paste that can be just rubbed 
through the sieve, otherwise the presence of much water will cause 
loss of carbon dioxide and yield a soft mass, which will not remain 
in separate granules while drying. The quantity of alcohol neces- 
sary will vary with the composition of the mixture; whenever citric 
acid or salts containing water of crystallization are present a lesser 
quantity should be used. Some substances contain an unusual 
amount of water of crystallization ; as, for instance, sodium sulphate 
55.87 per cent., sodium phosphate 60.31 per cent., magnesium sul- 
phate 51.13 per cent., etc.; this would interfere with proper granula- 
tion of the powder, and such salts must, therefore, be rendered either 
totally, or at least partially, anhydrous, by heating sufficiently before 
mixing with the other ingredients. 

AYell-tinned sieves must be used, through which the pasty mass is 
rubbed with the hands, otherwise the granules will not be perfectly 
white. A No. G or No. 8 sieve yields the most desirable size of gran- 
ules, from which the fine particles, which are invariably formed 
along with the coarser, can be readily separated by shaking in a No. 
20 or No. 30 sieve. 

All effervescent powders must be preserved in well-stoppered bot- 
tles, in a dry place, as they are inclined to attract moisture from the 
air, and thus rapidly deteriorate. 

Of the four effervescent salts recognized in the Pharmacopoeia, 
three are directed to be prepared in granular form, and one is simply 
a dry mixture of the powdered ingredients. The following is a list 
of the official preparations of this class and their composition : 

Effervescent Salts of the U S- Pharmacopoeia. 

N;iu:e. Composition. 

f Caffeine 10 Gm. 

Caffeina Citrata ' P 1 ^ Acid 10 



Effervescens 



\ Sodium Bicarbonate .... 330 
| Tartaric Acid . . . , .300 
1 Sngar 350 



Potassii Citras 
EtFervescens 



70 Gm. 
280 " 
370 " 
1000 " 

10 Gm. 

46 " 
34 " 

8 " 
90 Gm. 
63 " 

47 " 



368 PRACTICAL PHARMACY. 

Name. Composition, 

f Lithium Carbonate . 
Lithii Citras J Sodium Bicarbonate . 
EtFervescens ] Citric Acid 

[_ Sugar, sufficient quantity to make 
f Magnesium Carbonate 
Magnesii Citras ! Citric Acid .... 

Effervescens ] Sodium Bicarbonate . 

L Sugar ..... 

Potassium Bicarbonate 
Citric Acid .... 

Sugar ..... 

Special Remarks. 

Ccffeina Citrata Effervescens. The Pharmacopoeia very appro- 
priately calls this preparation " Effervescent Citrated Caffeine," since 
no definite chemical compound is formed between the caffeine and 
citric acid, although the solubility of the former is greatly increased 
by the presence of the acid. 

Lithii Citras Effervescens. This preparation is not officially directed 
to be in granular form, the well-dried iugredieuts beiug simply mixed 
in fine powder. Lithium citrate is not present in the mixture, but 
is formed at the time of solution of the powder, nor can the exact 
quantity of sugar necessary be stated in the formula, since the Phar- 
macopoeia directs the citric acid to be triturated with some of the 
sugar and the mixture to be thoroughly dried ; and, as citric acid 
contains about 8 per cent, of water of crystallization, the loss of this 
(wholly or in part) by drying must be replaced subsequently by addi- 
tion of sugar. A slight excess of citric acid (about J per cent.) is 
present in the finished product, which adds to the agreeably acidu- 
lous taste of the preparation when dissolved in water. 

Magnesii Citras Effervescens. In order to obtain a granular salt, 
which is readily and completely soluble, it is important that the offi- 
cial directions be closely followed. The addition of an excess of 
citric acid to the magnesium carbonate insures the formation of a very 
soluble acid magnesium citrate, provided the prescribed quantity of 
water only be used and the temperature of 30° C. (86° F.) be not 
exceeded during evaporation, otherwise the far less soluble normal 
salt is apt to be produced, causing trouble in the finished product. 
The remainder of the citric acid should be powdered separately and 
then mixed, without pressure, with the sodium bicarbonate and sugar; 
lastly the finely powdered magnesium citrate is added. The citric 
acid necessary for complete decomposition of the alkali bicarbonate 
is derived in part from the acid magnesium salt; although this 
changes the character of the latter compound, its ready solubility is 
nevertheless preserved by the newly formed sodium citrate. 

In England effervescent magnesium sulphate is extensively used, 
and a similar preparation is also sold in this country. The British 
Pharmacopoeia directs that 10 parts of crystallized magnesium sul- 
phate shall be heated at 54.4° C. (130° F.) until reduced to about 



GRANULAR EFFERVESCENT SALTS. 369 

three- fourths of its weight, when to the powdered residue are to be 
added 2.1 parts of sugar, 2.5 parts of citric acid, 3.8 parts of tartaric 
acid, and 7.2 parts of sodium bicarbonate, all in fine powder; the 
mixture is to be heated at between 93.3° and 104.4° C. (200° and 
220° F.) until the particles begin to aggregate, and then assiduously 
stirred until granules are formed. 

Potassii Citras Effervescens. The proportions of citric acid and 
potassium bicarbonate directed in the official formula are just suffi- 
cient for complete decompositiou, hence a neutral or normal salt will 
be formed. When the ingredients are triturated together in a warm 
mortar, reaction at once sets in, owing to the water present in the 
acid, hence the drying must be rapidly effected to prevent too great 
a loss of carbon dioxide. The paste may be formed into granules by 
rubbing through a No. 6 tinned sieve, or, if dried as a mass, it must 
be subsequently reduced to a coarse powder in a mortar. 



24 



CHAPTEE XXXIII. 

OINTMENTS AND CERATES. 

Both classes of these preparations are intended solely for external 
application ; they are of similar composition, of unctuous character, 
differing however from each other in degree of firmness aud fusi- 
bility. While the U. S. Pharmacopoeia officially recognizes the dif- 
ference between ointments and cerates, this distinction is not main- 
tained, as a rule, in Europe. The British and German Pharmaco- 
poeias designate both classes as ointments ; in France the term pom- 
made is applied to all ointments made with a purely fatty base, eveu 
if a small proportion of wax be present, while, the term onguent is 
only used if a resinous or similar substance has been added, the name 
cerat being reserved for mixtures of fat aud wax containing at least 
as much wax as our own cerates. 

In the preparation of ointments and cerates it is of importance 
that perfectly smooth, homogeneous mixtures be obtained, and that 
the fatty vehicle be absolutely free from rancidity, since they are often 
applied to tender excoriated surfaces, and would otherwise prove a 
source of irritation instead of a soothing application. Lumps or 
gritty particles in ointments indicate unpardonable carelessness on the 
part of the dispenser. 

Ointments and cerates made with yellow wax or resin are less 
liable to deterioration than when made with white wax, since the latter 
•during the bleaching process undergoes incipient rancidity ; they should 
be preserved in well-glazed, covered porcelain jars and kept in a dry, 
moderately cool place. The true porcelain jars, although somewhat 
expensive, are to be preferred, as they are strictly impermeable to 
grease and can be thoroughly cleaned with hot water and lye when- 
ever empty; the author had a set of these jars in constant use for 
over fifteen years without ever having an ointment turn rancid in 
them. Glass stock jars are offered at a much lower price, but will 
often crack while being cleaned, particularly with hot water, yet they 
are vastly superior to the ordinary white china or queens ware covered 
jar, since the glazing of the latter soon becomes full of fine cracks, 
through which the fat permeates and, gradually turning rancid, con- 
taminates the contents of the jar ; moreover, no amount of washing 
will remove the rancid grease entirely from the pores of the jars, 
hence they soon become unfit for use. The sweet condition of oint- 
ments and cerates cannot be preserved without proper care and clean- 
liness ; unfortunately these precautions are only too frequently disre- 
garded by pharmacists. 



OISTMEXTS AND CERATES 371 



Ointments. 



On account of their soft consistence, ointments are better suited 
for direct application to the skin by unction, when, becoming lique- 
fied by the heat of the body, they are readily absorbed. They may 
be conveniently divided into those consisting of plain, unctuous 
bodies and those composed of the desired remedial agent mixed with 
a suitable vehicle. The usual vehicle is lard, either plain or benzoin- 
ated (see page 191), to which, in southern latitudes or during warm 
weather, a small proportion of wax, 10 or 20 per cent., is often 
added ; besides lard, lanolin, petrolatum, and various mixtures of oil 
and wax are also employed. The lard to be used must be free from 
impurities (see page 190) and correspond to the official requirements. 
Hydrous wool-fat, or lanolin (see page 191), is, for many ointments, 
the most desirable vehicle that can be chosen, on account of its ready 
absorbability and its capacity for taking up large quantities of fluids 
(aqueous solutions of salts, as well as glycerin and alcoholic liquids) ; 
moreover, it is far more stable than lard. Lanolin can readily be 
combined with its own weight of water, whereas lard takes up only 
about one-fifth of its weight and soft paraffins not more than 10 per 
cent. Although petrolatum, vaseline, and similar soft paraffins are well 
adapted as ointment bases, on account of their indifferent chemical 
nature, they are ill-suited in some cases, owing to their very slow and 
imperfect absorption. 

The official glycerite of starch is sometimes used by physicians 
under the name of plasma or plasma glycerini as a vehicle for oint- 
ments, in place of lard or petrolatum. It possesses the advantage of 
not being of a fatty nature, and hence easily removed by washing with 
water, and never becoming rancid ; but as it is somewhat hygroscopic 
it must be preserved in well-closed jars. It is especially preferred 
by oculists for the application of lead acetate, mercuric oxide, and 
similar substances to the eyelids. A similar but somewhat firmer 
preparation is the glycerin ointment of the German Pharmacopoeia, 
also known in Europe as glycerolate. It is prepared by rubbing 10 
Gm. of wheat starch into a smooth mixture with 15 Gm. of water, 
adding 100 Gm. of glycerin, and finally a mixture of 2 Gm. of pow- 
dered tragacanth and 5 Gm. of alcohol ; the whole is heated on a 
steam bath or over a direct fire with constant stirring until the alcohol 
has all been dissipated and a transparent jelly-like mass results. 

Dermatologists have long been looking for an ointment base or 
vehicle which, while non-irritating, should not be of a greasy nature 
if possible, so as to render its use more convenient and agreeable to 
patients. Numerous substances have been suggested, such as solvine 
or polysolve and oleite, which are alkali sulpho ricinoleates, and as 
such miscible with water, gelatole, a mixture of oleite and gelatin, and 
similar semi-solid preparations, to be applied in the form of a thin 
layer or varnish-like coating. The most successful in this respect 
appears to have been a vehicle composed of casein, glycerin, and soft 



372 PRACTICAL PHARMACY. 

paraffin, which is used in Europe under the name unguentum caseini. 
Unfortunately the exact proportions of the ingredients and the mode 
of combining them are kept a secret by the manufacturers, but, accord- 
ing to their published statements, pure casein is dissolved in water 
by means of a small quantity of potassium or sodium hydroxide, the 
solution being then mixed with glycerin and vaseline or soft petro- 
latum and the resulting white emulsion further preserved by ben- 
zoinating it ; the finished preparation resembles very soft cold cream 
or thick condensed milk, and is said to be readily removed from the 
skin with water. 

As regards the mode of preparation of ointments, three distinct 
methods are followed, namely, by fusion, by incorporation of the 
medicinal agent with a suitable vehicle, and by chemical action. 
When ointments are to be made by fusion those constituents having 
the highest fusing-point, as resin, wax, and spermaceti, should be 
heated first, and, when nearly melted, the lard or oil added, bearing 
in mind that, as long as some of the particles remain unmelted, there 
is no danger from the continued application of heat, which should, 
however, be withdrawn in time to avoid a rise in temperature of 
the melted fats (see page 85). Fusion of ointments is preferably 
performed on a water-bath, in round-bottom pans or evaporating 
dishes, and, if dirt be present, the melted mixture may be decanted, 
or, if necessary, strained through cheese-cloth into a previously 
warmed dish or mortar ; the liquid should then be stirred until a 
homogeneous soft mass results, after which it may be set aside and 
allowed to stiffen by further gradual cooling. The stirring of melted 
fats while cooling is essential to insure a perfectly smooth product, 
since fats are composed of solid and liquid bodies, which, during the 
cooling process, become partially separated, producing a granular 
solid on congealing, if allowed to cool at perfect rest, as may be seen 
in the case of plain lard ; moreover, in a mixture of melted fats, 
those having a higher fusing-point would naturally congeal earlier 
than the rest ; therefore, unless an intimate mixture be kept up by 
constant stirring separation would ensue and a lumpy ointment result. 
The point of danger may be said to have been passed when the 
melted ointment has so far cooled down under continued stirring 
that a uniform thick, creamy mass is obtained; for stirring a broad 
wooden spatula will be found advantageous. When large quantities 
of aqueous liquids are to be incorporated with melted fats, as in the 
case of rose-water ointment, the liquid should be warmed and then 
slowly added, with constant trituration, to the mixed fats previously 
somewhat cooled ; otherwise the less fusible constituents will be chilled 
by the cold liquid and separate in granular form, thus preventing a 
smooth ointment. The following ointments are officially directed to 
be made by fusion : 



OIXTJIEXTS AND CERATES. 373 



Name. 

uentum . 


•{ 


Composition. 
Lard .... 
Yellow Wax . 


80 Gm. 
20 " 


Aqiife Kosre . 


f 

1 
I 


Spermaceti 
White Wax . 
Expressed Oil of Almond 
Stronger Rose Water . 
Sodium Borate 


125 Gm, 

120 " 
600 Cc 
190 " 
5 Gm. 


Diachylon 


{ 


Lead Plaster . 

Olive Oil 

Oil of Lavender 


500 Gm. 

490 " 

10 " 


Picis Liquidse 


'•{ 


Tar .... 
Lard .... 
Yellow Wax . 


500 Gm. 
375 " 
125 " 



The addition of borax to the official rose-water ointment gives the 
latter a whiter and more creamy appearance, but at the same time 
interferes with the admixture of certain chemicals, such as calomel, 
yellow mercuric oxide, etc., causing discoloration of the ointment. 
Vegetable or mineral powders cannot be mixed in quantity with rose- 
water ointment without forcing the water out of combination. 

Unless the lead plaster for diachylon ointment be fresh it is best 
to remove the darkened dry exterior, thus obtaining a lighter- colored 
and softer ointment; the oil must be added when the plaster is nearly 
melted on a water-bath, and a better mixture will result if the heat 
be continued for 5 or 10 minutes afterward, so as to blend the oil and 
plaster more thoroughly. The melted mixture must be stirred until 
creamy, when the oil of lavender may be added, the whole transferred 
to a jar and allowed to cool. Diachylon ointment is preferably pre- 
pared fresh when wanted, as it does not keep well. 

In preparing tar ointment the tar should be free from granular 
matter and not incorporated with the mixture of lard and wax until 
the latter has been cooled down to the condition of a smooth, soft 
ointment. If the tar be added to the hot liquid fats, a granular oint- 
ment will result. 

Ointments prepared by incorporation of medicinal agents with an 
appropriate vehicle comprise by far the larger number of official 
ointments, and practically all those prescribed extemporaneously. 
Benzoinated lard and simple ointment are alone directed by the Phar- 
macopoeia as vehicles, although physicians frequently use petrolatum 
or the commercial products known as vaseline and eosmoline; when 
absorption of the ointment is desired wool-fat, known as lanolin, is 
decidedly to be preferred. All substances to be mechanically incor- 
porated in an ointment must be in the form either of solution or an 
impalpable powder; the latter condition, in the case of vegetable 
substances, can be attained only by passing the powder through a 
fine bolting-cloth sieve (about No. 120 or 150). The incorporation 
may be effected either in a mortar or on a heavy glass slab by means 
of a broad spatula, the finely powdered substance being first mixed 
with a small quantity of the vehicle, and, when a smooth mixture 
has been obtained, the remainder added; while an ointment slab is, 



374 PRACTICAL PHARMACY. 

as a rule, preferred in this country the mortar is used almost exclu- 
sively in Europe, aud, for some ointments, is in fact indispensable, 
particularly when solutions are to be added. 

When the quantity of powder to be added is large it will prove 
advantageous to melt some of the vehicle and mix this with the pow- 
der, in a warm mortar, before adding the remainder. Some sub- 
stances can be conveniently brought into a smooth condition by tri- 
turating with a little olive or expressed almond oil, such as calomel, 
lead carbonate, bismuth subnitrate, zinc oxide, etc., as well as certain 
crystallizable bodies, like mercuric chloride and silver nitrate ; for the 
latter a little oil is decidedly better than water, since, upon the 
gradual evaporation of the latter, a return to the crystalline state is 
probable, giving rise to the presence of minute gritty particles which 
would cause irritation. Opium should be rubbed smooth with about 
an equal weight of water, and then at once incorporated with the 
fatty vehicle before the paste begins to dry ; solid extracts are treated 
in like manner, enough water or, in some cases, diluted alcohol being 
used to produce a thick, syrupy liquid. Some salts may be dissolved 
in water, provided they are very soluble, as potassium iodide, while 
others must be reduced to an impalpable condition by trituration, 
as lead acetate, tartar emetic, zinc sulphate, etc. Eed mercuric oxide, 
iodoform, naphtalene, and boric acid may be triturated with a few 
drops of alcohol, in a mortar, until rendered impalpable; camphor 
should be powdered, by the aid of alcohol, just before it is to be used, 
and added to the ointment after all other ingredients have been in- 
corporated, since it is soluble in the fat and materially softens its 
consistence, which, in the case of solid extracts, would interfere con- 
siderably with their perfect admixture. 

Iodine, before admixture of fats, is preferably dissolved in a small 
quantity of water, with the aid of a little potassium iodide, as it can- 
not readily be rubbed into a very fine powder by itself; the addition 
of alcohol is sometimes employed to facilitate the division of the 
iodine, but this plan never yields so satisfactory an ointment. 

When iodine is ordered in combination with mercurial ointment, 
the addition of potassium iodide is unnecessary, as chemical union 
will take place between the iodine and mercury ; the proper plan 
would be to rub the iodine into a fine powder and then add a portion 
of the mercurial ointment, triturating well until the iodine has dis- 
appeared and the change in color indicates that union has taken place, 
after which the remainder of the ointment may be incorporated. If 
an extract, such as belladonna or stramonium, is also to be added, this 
should be separately mixed with some of the fat and then added to 
the previous mixture, whereby a much better ointment will be obtained. 

Substances which are wholly or partly soluble in fats, such as men- 
thol, salol, chrysa robin, benzoic and carbolic acids, aristol, naphtol, 
and the like, should be triturated, in fine powder form, with a por- 
tion of the vehicle liquefied by heat, and, after addition of the re- 
mainder, the mixture must be continually stirred until cold. If 



OIS TMESIS ASD CERATES. 375 

chloral, thymol, naphtol, or salol be ordered, together with camphor, 
in an ointment, the two substances must be triturated together until 
an oily fluid results, which can then be readily incorporated with 
the vehicle. 

Alkaloidal salts may be incorporated in ointments in solution in 
water or, if present in large quantity, may be added in form of a very 
fine powder; but whenever pure alkaloids are ordered by physicians 
these should be triturated with a small quantity of warm oleic acid, 
before they are mixed with the fatty vehicle, as more intimate dis- 
tribution is thus effected than if the alkaloids be merely rubbed into 
a smooth paste with olive or almond oil. 

Glycerin should never be used in place of oil or water to produce 
a smooth paste with vegetable or mineral powders, because, although 
derived from fats, it can be incorporated with them permanently only 
with difficulty. When glycerin in considerable quantity is ordered 
to be added to an ointment consisting chiefly of lard or a mixture of 
lard or oil with wax, the addition of a small proportion of anhydrous 
wool-fat, in place of a like quantity of the regular vehicle, will over- 
come all difficulty of incorporation. A similar expedient will prove 
most valuable when large quantities of aqueous fluids are to be in- 
corporated in ointments, or in the case of alcoholic liquids which, ordi- 
narily, mix with fats with great difficulty. The pharmacist, in pre- 
paring ointments containing fluids, must so combine the constituents 
that a permanent homogeneous mixture results, from which the fluids 
will not separate on standing. 

It will be found very convenient to keep on hand anhydrous wool-fat 
for the purposes above stated; it is readily prepared by heating some 
of the commercial lauolin (containing about 30 per cent, of water) 
on a water-bath, until it ceases to lose weight. 

When two or more ointments having different fusing-points are 
to be mixed, the firmer should always be rubbed down by itself first, 
and the softer fats be then incorporated in small quantities at a time, 
otherwise an imperfect mixture results. A mixture of mercurial 
ointment with lard or simple ointment offers an example; in cold 
weather this mode of procedure is all the more imperative; it should 
also be followed when anhydrous wool-fat is to be mixed with softer 
fats, as the former is usually somewhat tough. 

Whenever substances likely to attack metal are ordered in oint- 
ments the incorporation with the fatty vehicle should never be 
made with steel spatulas, but always with horn or rubber-coated 
ones; the latter can now be had quite pliable, and are admirably 
adapted for ointments containing tannic acid, iodine, mercuric chlo- 
ride, etc. 

The Pharmacopoeia directs the following eighteen ointments to be 
prepared by incorporation of the medicinal agent with the fatty 
vehicle ; of the latter, except in one case, benzoinated lard and the 
official simple ointment alone are used : 



376 



PRACTICAL PHARMACY. 



Active Iogredient. 






Vehicle. 




Carbolic Acid . 


5 per ct. 


Ointment- 


Tannic Acid . 


20 


" 


Benzoinated Lard 


Extract of Belladonna Leaves 


10 


" 


a tt 


Chrysarobin . 


5 


tt 


a a 


Powdered Nutgall . 


20 


tt 


it a 


Mercury 


50 


it 


Lard and Suet. 


Ammoniated Mercury . 


10 


it 


Benzoinated Lard 


Yellow Mercuric Oxide . 


10 


a 


Ointment. 


Red Mercuric Oxide 


10 


ti 


tt 


Iodine 


4 


it 


Benzoinated Lard 


Iodoform 


10 


a 


tt 


t 


Lead Carbonate 


10 


a 


a 


< 


Lead Iodide . 


10 


a 


a 


t 


Potassium Iodide . 


12 


a 


a 


t 


Extract of Stramonium Seed 


10 


tt 


tt 


t 


Washed Sulphur . 


30 


ti 


a 


t 


Veratrine 


4 


a 


tt 


t 


Zinc Oxide 


20 


a 


a 


t 



Name. 
Unguentuin : 
Acidi Carbolic! , 

Tannici, 
Belladonnse, 
Chrysarobin i, 
Gallae, 
Hydrargyri, 

Ammoniati, 

Oxidi Flavi, 

Oxidi Rubri, 
Iodi, 

Iodoformi, 
Plumbi Carbonatis, 

Iodidi, 
Potassii Iodidi, 
Stramonii, 
Sulphuris, 
Veratrini, 
Zinci Oxidi, 

The official directions accompanying each formula and the general 
directions given above are sufficiently explicit to insure satisfactory 
ointments, therefore further comment is unnecessary, except in two 
or three cases. 

The extinguishment of mercury by means of oleate of mercury, 
in the preparation of mercurial ointment, is readily eifected by tri- 
turation in a mortar on a small scale, but large manufacturers prob- 
ably follow the plan of prolonged agitation in suitable vessels. When 
the globules of mercury have become invisible the mixture of lard 
and suet, melted and partly cooled, is easily incorporated. The com- 
mercial variety of mercurial ointment, known as one-third mercury, 
is nearly 17 per cent, weaker than the official, and should not be used 
in prescriptions. In very warm weather mercurial ointment may 
become almost liquid, and is then liable to loose mercury by separa- 
tion, hence the necessity for keeping it in a cool place. When mer- 
curial ointment is prescribed in divided doses by physicians, each 
portion should be separately weighed on paraffin or parchment paper, 
and then folded as directed in the chapter on powders. 

Ointment of red oxide of mercury is apt to become discolored 
when rancid : hence, if it is to be kept on hand for some time, a better 
vehicle than lard and wax may be employed. A mixture of one part 
of yellow wax and three parts of castor oil will not turn rancid, and, 
if with this be incorporated the proper proportion of finely pow- 
dered red mercuric oxide, the ointment can be kept for months with- 
out change. 

The addition of sodium thiosulphate (hyposulphite) to ointment of 
potassium iodide is for the purpose of preserving its white appear- 
ance ; without this addition it will turn yellow and finally brownish, 
owing to a gradual liberation of iodine. In the formula of the 
British Pharmacopoeia potassium carbonate is directed to be added 
for the same purpose. 

Of the ointments made by chemical action, the official ointment of 



OINTMENTS AND CERATES. 377 

mercuric nitrate is a striking example. When lard oil is heated and 
mixed with nitric acid, the former undergoes oxidation at the expense 
of the acid, olein being converted into a new compound, solid at 
ordinary temperatures, known as elaidin, the term olein being usually 
applied to the fluid constituent of fat and fixed oils. The incorpora- 
tion of the solution of mercuric nitrate subsequently with the elaidin 
is simply a mechanical admixture, the solution having no chemical 
effect whatever on the fat. It is essential that the nitric acid be of 
official strength, and that heat be reapplied, if necessary, to complete 
the oxidation of the fat; the heat of a boiliug-water-bath only should 
be used, however, as over a direct fire decomposition of the fat is apt 
to ensue and a dark brown compound result, whereas, on the water- 
bath, not more than a deep orange color is produced. The oxidation 
of the lard oil goes on quietly, and is known to be ended when effer- 
vescence ceases and a soft solid mass is obtained upon cooling. The 
solution of mercury in nitric acid can be made in the cold, and may be 
warmed finally to expel any colored gas that has been retained. If 
the fat has been properly oxidized and cooled down, as directed in 
the Pharmacopoeia, the mercuric nitrate solution will not suffer re- 
duction when added, and a bright lemon-yellow ointment will result, 
if the mixture be stirred until cold with a glass or wood spatula. 
Ointment of nitrate of mercury should never be brought into con- 
tact with metal, to avoid precipitation of finely divided mercury. 

Another instance of chemical reaction in the preparation of oint- 
ments is in the original formula for Hebra's ointment ; lead oxide is 
heated with olive oil, in the presence of water, until all the oxide has 
chemically combined with the fatty acids derived from decomposition 
of the oil, the newly-formed lead oleate remaining intimately mixed 
with the excess of oil and the glycerin liberated from the fat. The 
decomposition taking place will be more fully explained under the 
head of Saponification in Part III. The original Hebra's ointment 
differs from the official diachylon ointment in containing some free 
glycerin. 

Ointments should always be dispensed in glass or porcelain jars 
provided with suitable covers ; if the latter be of metal or wood, a 
disk of heavy paraffin paper should be inserted to avoid contact with 
the fatty substance. Under no circumstances, except when intended 
for immediate use only, should ointments be put up in wood-boxes, as 
the fat will readily penetrate the material, and thus become exposed 
to oxidation by the air. When ointment jars are returned to be re- 
filled they should be carefully wiped out with soft paper and washed 
thoroughly before the new ointment is put in ; a fresh disk of paraffin 
paper should also be inserted and a new label be put on the jar if the 
old one has become soiled. 

To cleanse the apparatus in or on which ointments have been pre- 
pared the best plan is first to wipe off all remaining grease with clean 
sawdust or soft paper and then to wash it well with warm water and 
lye or soap. In the case of iodoform ointment a few r drops of oil of 



378 PRACTICAL PHARMACY. 

turpentine will remove the characteristic odor readily, as already 
stated on page 316. 

Cerates. 

This class of preparations differs from ointments in the presence 
of a considerable proportion of wax, and frequently also of resin 
or oleoresinous substances. Cerates are intended to be applied as 
dressings, usually spread on linen or soft leather ; while they become 
somewhat softer at the temperature of the body, they do not liquefy, 
and are intended to act only locally. What has been said before re- 
garding the preparation of ointments by fusion, and also their pre- 
servation, applies likewise to cerates ; owing to their firm consistence 
the latter are not well adapted to admixture with powdered sub- 
stances, although fluids are sometimes incorporated with them. 

The Pharmacopoeia recognizes six cerates, which, with the excep- 
tion of the cerates of lead subacetate and of spermaceti, are usually 
carried in stock by the pharmacist. Two of the official cerates con- 
tain resin, and, in these, yellow wax is also used ; hence there is no 
danger of rancidity. The other four are made with white wax and 
lard or oil ; if benzoinated lard were used in place of plain lard, these 
cerates would keep much better. 

The following is a list of the official cerates, showing their com- 
position : 



Name. 




Composition. 








•{ 


White Wax .... 


30' 


parts, 


itum 


Lard 


70 


U 




( 


Camphor Liniment 


10 


u 


Camphorse 


1 


White Wax .... 
Lard 


30 
60 


(I 
ti 




f 


Powdered Cantharides 


32 


it 






Yellow Wax 


18 


a 


Cantharidis . 


. -1 


Resin ..... 


18 


ti 






Lard .... 


22 


a 




I 


Oil of Turpentine 


10 


a 




r 


Spermaceti .... 


10 


u 


Cetacei . 


• 


White Wax. . . . 


35 


a 




1 


Olive Oil . . . . 


55 


a 


Plumbi Subacetatis 


•I 


Solution of Lead Subacetate 
Camphor Cerate . 


20 
80 


ti 
ti 




r 


Resin . 


35 


a 


Eesinse . 


• 


Yellow Wax 


15 


a 




1 


Lard 


50 


u 



Camphor cerate contains but 2 per cent, of camphor, and is used 
only in the preparation of Goulard's cerate ; the amount of camphor 
is not sufficient to impart marked medicinal properties to the cerate. 

In the formula for cantharides cerate the powdered cantharides are 
directed to be macerated with oil of turpentine for forty-eight hours 
before adding the lard, wax, and resin, previously melted together, for 
the purpose of facilitating the subsequent solution of the blistering 



OIXTMEXTS AND CERATES. 379 

principle in the fats, as turpentine is known to exercise a ready 
solvent effect on cantharidin, the active principle of Spanish flies. 
The excess of turpentine is dissipated during the subsequent diges- 
tion on the water- bath, and, as the powdered can thar ides are not re- 
moved by straining, it is important that the mixture be continually 
stirred, when removed from the bath, until cool. In Great Britain, 
France and Germany this cerate is known as Emplastrum Can- 
tharidis or E. Yesicans. 

The incorporation of solution of lead subacetate with camphor 
cerate, in the preparation of Goulard's cerate, is more easily accom- 
plished, especially in cold weather, if the camphor cerate be first 
softened a little by trituration. The finished product contains about 
5 per cent, of basic lead acetate and 1.6 per cent, of camphor. 

The official resin cerate congeals as a perfectly homogeneous mix- 
ture upon cooling without stirring on account of the large propor- 
tion of resin and wax present; stirring of the melted and strained 
mixture is, in fact, not desirable in this case, as it incorporates con- 
siderable air. Resin cerate gradually grows tougher by age. 



CHAPTEK XXXIV. 

LINIMENTS AND OLEATES. 

These preparations are closely allied to those described in the pre- 
ceding chapter, being also intended only for external use. 

Liniments. 

Liniments are fluid or semi-fluid preparations, usually in the form 
of solutions, although, in some instances, merely mechanical mix- 
tures, the solvent or vehicle being either a fixed or volatile oil or 
alcohol, which latter is sometimes mixed with water. They are 
always applied to the skin by friction, and, when mechanical mixtures 
only, require to be well agitated before they are applied. The pres- 
ent Pharmacopoeia recognizes nine liniments, of which four are of a 
fatty nature, while five are alcoholic or hydro-alcoholic solutions ; 
with two exceptions, they are usually prepared extemporaneously, 
although they keep well. 

When fixed oils are shaken with aqueous solutions of alkalies, par- 
tial decomposition of the fat takes place, and an emulsion-like mixture 
results, in which the remaining oil is kept in perfect suspension by 
the newly formed soap ; such liniments thicken considerably by age, 
which it is intended to provide against in the official formula for 
ammonia liniment, by the addition of alcohol. If the fixed oils used 
are fresh and perfectly sweet, they are but little acted on by alkalies 
in the cold, hence the preparation of a perfect liniment becomes diffi- 
cult. 

The following; is a list of the official liniments: 



Name, 
Linimentum Ammonise 

Belladonnas 

Calcis . 
Camphorge . 
Chloroformi 



Composition. 




C Ammonia Water 
. < Cotton-seed Oil 
( Alcohol . 


. 35 Cc. 
. 60 " 
. 5 " 


( Camphor .... 5 Gm. 
. \ Fluid Extract of Belladonna, 
(. sufficient to make . . 100 Cc 


•{Mn^oTl}" 


. 50 Cc. 


f Camphor . 

\ Cotton-seed Oil 


. 20 Gm. 

. 80 " 


/ Chloroform 
' \ Soap Liniment . 


. 30 Cc 

. 70 " 



LINIMENTS AND OLEATES. 381 

Name. Composition. 

f Powdered Soap . . 7 Gm. 

Camphor . . . . 4.5 " 

Lininientum Saponis . . -j Oil of Kosernary . 1 Cc. 

Alcohol . . . . 75 " 

[ Water sufficient to make . 100 4 ' 

f Soft Soap . . . .65 Gm. 

• i\r it Gil of Lavender . . 2 Cc. 

Saponis Mollis . . . \ Alcohol m „ 

[ Water sufficient to make .160 " 
f Volatile Oil of Mustard . 3 Cc 
| Fluid Extract of Mezereum 20 " 
Sinapis Compositum . . ■{ Camphor .... 6 Gm 
| Castor Oil 15 Cc 

(_ Alcohol sufficient to make 100 '' 

Resin Cerate . . .65 Gm. 

Oil of Turpentine . . 35 " 



Terebinthinte 



1 



Special Remarks. 

The cotton-seed oil of the market does not seem well adapted for 
the preparation of ammonia liniment, separation into two distinct 
layers invariably occurring in the official mixture ; if the cotton-seed 
oil be replaced in part — 15 or 20 per cent. — by olive oil, and particu- 
larly common olive oil, which usually contains some free fatty acids, 
a much more satisfactory liniment will be obtained. Ammonia lini- 
ment is also known as volatile liniment, from the volatile nature of 
the alkali used. Camphorated ammonia liniment, recognized in the 
German and French Pharmacopoeias, is made from camphor liniment 
in place of plain fixed oil. 

In the preparation of camphor liniment, the solution of the cam- 
phor can be materially hastened by placing it, with the oil, in a 
strong bottle and, after corking the same securely, digesting the mix- 
ture on a water-bath at a moderate heat. 

Chloroform liniment of the United States Pharmacopoeia differs 
materially from that of the British Pharmacopoeia ; the latter is a 
mixture of equal volumes of chloroform and camphor liniment. A 
very popular preparation, known as Compound Chloroform Lini- 
ment, is composed of one volume each of chloroform and tincture of 
aconite and six volumes of soap liniment. 

Powdered soap, as directed in the Pharmacopoeia, is to be much 
preferred in making soap liniment, on account of the variable quan- 
tity of moisture present in the official soap. The liniment can be 
more quickly prepared if the soap be heated with about three times 
its weight of water, iu a dish, on a water-bath, until a uniform gelat- 
inous mass results, which will dissolve almost immediately when 
mixed with one-half the prescribed quantity of alcohol ; the cam- 
phor and the oil of rosemary having been dissolved in the remainder 
of the alcohol by agitation, are then added to the soap solution, fol- 
lowed by sufficient water to make the required volume. The official 
directions to set the liniment aside 1 in a cool place for twenty-four 
hours, and then to filter, are for the purpose of getting rid of the 



382 PRACTICAL PHARMACY. 

sodium palmitate always present in castile soap, which is but spar- 
ingly soluble in the menstruum, particularly in the cold. 

The official turpentine liniment is also known as " Kentish " lini- 
ment ; only a moderate heat should be employed to melt the resin 
cerate, so as to avoid volatilization of the oil of turpentine, which 
must also be added in small quantities, with constant stirring, until 
a smooth, uniform, opaque mixture results. 

Oleates. 

This class of preparations has been in use by physiciaus in this 
couutry since 1872. Normal oleates are true chemical compounds of 
oleic acid with metallic oxides or alkaloids, but the oleates medicinally 
employed are simply mixtures of such normal oleates with oleic acid 
or some other diluent. The proportion of any particular metallic 
oxide or alkaloid to be dissolved in oleic acid may vary with the 
views of the physician ; but, in the case of normal oleates, a certain 
proportion cannot be exceeded. The expressions 2, 5, 10, or 20 per 
cent, oleate are used to indicate that 2, 5, 10, or 20 parts of the re- 
spective alkaloid or metallic oxide are present in every 100 parts of the 
finished product. The following table shows the amount of base 
combined with oleic acid in 100 parts of the respective normal 
oleates : 



Normal Oleate of Iron (ferric) 


8.9 pei 


r cent. 


of anhydrous ferric oxide. 


it 
It 


a 
it 


Copper 
Zinc 


12.7 
12.9 


a 
a 


" cupric oxide. 
" zinc 


a 


a 


Bismuth 


22.2 


a 


" bismuth " 




a 


Mercury 


28 4 


a 


" mercuric " 


a 


a 


Lead 


29.0 


a 


" lead 


a 
u 
a 


a 
t. 
it 


Morphine 

Atropine 

Cocaine 


50.3 
50.6 
51.8 


a 
a 
a 


" morphine 
" atropine. 
" cocaine. 




a 
a 


Quinine 
Strychnine 


53.46 
54.22 


it 
it 


" quinine. 
" strychnine 


a 


a 


Veratrine 


61.15 


it 


" veratrine 


a 


a 


Aconitine 


69.6 


a 


" aconitine. 


(The last named two 


proportions are 


based on 


the formulae given by Prescott for 


pure aconitine and 


veratrine ) 









From these normal oleates weaker preparations can readily be 
made by admixture with the desired diluent, according to the well- 
known rule already given on page 66. Multiply the desired quantity 
by the desired percentage strength and divide the product by the per- 
centage of the normal oleate ; the quotient will indicate the quantity 
of normal oleate to be used, and subtracting this from the desired 
quantity gives the weight of the diluent necessary. 

Solutions of alkaloidal oleates are best prepared by triturating the 
prescribed quantity of dry alkaloid in a small dish, with the neces- 
sary weight of oleic acid, and heating the mixture somewhat on a 
water-bath until perfect solution results ; they are, as a rule, of 2 
per cent, strength, with the exception of morphine and cocaine, 



LINIMENTS AND OLEATES. 383 

usually of 5 per ceut. strength, and quinine frequently prescribed of 
25 per cent, strength. As alkaloidal oleates are always intended to 
act constitutionally, and therefore must be absorbed, oleic acid only 
should be used in their preparation, and no other diluent be added. 
The necessary amount of alkaloid and acid for any given weight of 
solution, can be quickly calculated by the rules given on page 114 
under Percentage Solutious. 

The solution of metallic oxides in oleic acid is effected very slowly 
even with the aid of heat, hence they are preferably prepared by 
mutual decomposition, by adding an aqueous solution of the metallic 
salt to a solution of an alkali oleate. The precipitated metallic 
oleates are then washed with water to free them from the newly 
formed alkali salt ; with the exception of mercuric oleate, they may 
all be washed with hot water, two or three washings being quite suffi- 
cient, but for mercuric oleate only warm water must be employed 
to avoid decomposition. Metallic oleates are usually prepared of 
normal strength, as they keep better in this form and can be subse- 
quently diluted as wanted. With the exception of mercuric oleate, 
the metallic oleates are intended for local medication, hence benzoin- 
ated lard or soft paraffins are employed as diluents. As mercuric 
oleate is intended to be absorbed, no other diluent than oleic acid 
should be used ; sometimes, however, physicians prefer dilution with 
lanolin. 

A solution of castile soap is very often used as the alkali oleate in 
the preparation of metallic oleates, especially those of lead, copper, 
and zinc ; but since the soap is a sodium oleopalmitate, instead of 
pure sodium oleate, the resulting metallic oleates will also be con- 
taminated with palmitates ; in practice, this slight impurity is gener- 
ally disregarded, and can be reduced to a minimum by allowing the 
soap solution to stand in a cool place for twenty-four hours and then 
filtering. The strength of the soap solution generally used is one 
ounce of dry soap to the pint. Purer metallic oleates can be ob- 
tained by using a solution of sodium oleate made directly from offi- 
cial oleic acid by the following process : Warm, in a capacious dish, 
1217 grains of oleic acid to about 60° or 65° C. (140° to 149° F.) 
and add slowly 192 grains of official soda (90 per cent.) dissolved in 
a mixture of two fluidounces of distilled water and six fluidrachms 
of alcohol, stirring constantly until the acid is neutralized, which is 
best ascertained by testing a small portion of the resulting soap, dis- 
solved in alcohol, with a few drops of phenolphtalein solution — not 
more than a faint pink tint should appear. The soap is next dis- 
solved in three pints of water and filtered. A solution of potassium 
oleate of about the same strength may be obtained if to one pint of 
boiling water be added 410 grains of potassium bicarbonate and 
afterward 1156 grains of oleic acid, the mixture being boiled until 
the acid has all been taken up and a clear soap solution results, 
which, when cold, is diluted to three pints by addition of water. To 
one pint of either of these alkali oleate solutions may be added one- 



384 PRACTICAL PHARMACY. 

half pint of a metallic salt solution containing the following quanti- 
ties of the salt : 

For one pint of sodium oleate solution : 

Lead Acetate, crystallized ...... 273 grains. 

Copper Sulphate, crystallized . . . . . . 180 " 

Zinc Sulphate, crystallized ...... 207 " 

Mercuric Nitrate 237 " 

For one pint of potassium oleate solution : 

Lead Acetate, crystallized ...... 259 grains. 

Copper Sulphate, crystallized . . . . . 170 " 

Zinc Sulphate, crystallized . . . . . 197 " 

Mercuric Nitrate 225 " 

The United States Pharmacopoeia recognizes but three oleates, all 
made by direct solution of the active ingredient in oleic acid ; they 
are : 

Oleate of mercury containing 20 per cent, of mercuric oxide, oleate 
of veratrine containing 2 per cent, of veratrine, and oleate of zinc 
containing 5 per cent, of zinc oxide. 

The first named is of the consistence of firm butter, the second is 
a liquid, and the last named is like a soft ointment. 

Powdered oleate of zinc should be the true normal oleate, but the 
commercial article is frequently mixed with an excess of zinc oxide ; 
it is best prepared by the process suggested by Mr. Beringer, which 
is as follows : Warm the sodium oleate solution (see page 383) to 43° 
C. (109.4° F.), and to it add slowly, with constant stirring, the solu- 
tion of zinc sulphate, collect the precipitate on a moist filter, wash 
thoroughly with water, and dry, on bibulous paper, at a temperature 
of not above 38° C. (100° F.). In order that the oleate, when dry, 
may be obtained in white friable masses which can easily be passed 
through a sieve as an impalpable unctuous powder, it is important 
that the temperature during precipitation be maintained between 38° 
and 43° C. (100° to 110° F.). 

Under the names of ointments of the various oleates, manufac- 
turers have for some time offered a class of preparations in regard 
to which some confusion exists, as the vehicle as well as the propor- 
tion of the oleate used varies with different manufacturers; the vehi- 
cle is either benzoinated lard or soft or firm petrolatum, hence the 
consistence may vary considerably. The term " ointment of any 
oleate, 5, 10, or 20 per cent.," can have but one meaning as far as the 
active ingredient is concerned, namely, that the finished product con- 
tains 5, 10, or 20 parts of the respective normal oleate in every 100 
parts of the ointment, and not 5, 10, or 20 parts of the alkaloid or 
metallic oxide, as is frequently supposed. Ointments of oleates are 
officially recognized in only one instance, the ointment of zinc oleate 
of the British Pharmacopoeia, which is composed of equal parts of 
10 per cent, zinc oleate and soft paraffin. 



CHAPTEE XXXV. 

PLASTERS AND SUPPOSITORIES. 

Plasters. 

Plasters are preparations intended for external application, 
which, although firmer and more tenacious than cerates, become 
adhesive by the heat of the body, and can be made to serve the double 
purpose of offering both support and medication to the parts to which 
they are applied. They are firm solids at ordinary temperature and 
cannot be spread without the aid of heat, but retain a certain degree 
of flexibility when applied to the body. The base or mass of all 
plasters made by pharmacists is either simple-lead plaster or a mix- 
ture of the same with wax, resin, and gum-resins ; in large manu- 
factories a rubber mass is specially prepared from caoutchouc and 
certain aromatic resins, w T hich is greatly to be preferred on account 
of its flexibility and adhesiveness. It admits of the ready incor- 
poration of various medicinal agents aud possesses many advan- 
tages over the ordinary lead-plaster and resinous bases. In the 
preparation of the rubber plaster-base the crude India rubber of com- 
merce is first freed from impurities, by steaming and continuous 
washing with warm water, in suitable machinery, until all foreign 
matter has been removed, after which it is repeatedly passed between 
heavy steel rollers kept at a temperature of about 35° or 37° C. (95° 
or 98.6° P.); during this kneading process the rubber gradually 
softens aud assumes a plastic condition which fits it admirably for 
the incorporation of very finely powdered olibanum and resin or 
Burgundy pitch, this being also effected between warm, smooth 
rollers. 

The preparation of plasters by pharmacists is very similar to that 
of cerates, being preferably conducted with water-bath heat, those 
constituents having the highest fusing-point being first introduced 
into the pan or dish, and others of greater fusibility being gradually 
incorporated. All wholly or partly volatile substances, as oleo-resins 
or essential oils, must be added last, and non-fusible substances must 
be incorporated in the form of very fine powder whenever possible ; 
as gum-resins are frequently added to plaster mixtures, and as they 
cannot be reduced to fine powder without injury, they must either be 
treated in coarse powder with alcohol, and the resulting solution of 
resinous matter then evaporated to a thick, syrupy consistence, as in 
the case of asafetida, myrrh, and galbanum, or be emulsionized with 
diluted acetic acid and then evaporated until the liquid hardens on 
cooling, as in the case of ammoniac. In either case the concentrated 

25 



386 PRACTICAL PHARMACY. 

liquid should be added to the fused mixture when it begins to cool, 
the mass being well stirred to insure uniform distribution. 

Fluid and solid extracts must be incorporated as in the case of 
ointments, the former after evaporation to a syrupy consistence, the 
latter after softening down with diluted or strong alcohol, as the case 
may be. As in the case of ointments, the extinguishment of metallic 
mercury in plasters is most conveniently effected by trituration with 
mercuric oleate. 

If any foreign matter, such as sand, pieces of wood, and the like, 
should be found in the melted plaster, this is best removed by de- 
cantation or straining, which must always be done before the insoluble 
and non-fusible substances are added ; if straining be resorted to, it 
will be advisable to perform this operation with the smallest bulk 
possible, the strained material being always received in a warm pan 
or dish. 

If plasters are to be preserved for stock, they are usually rolled 
into cylindrical pieces of convenient thickness weighing about 4 or 
8 oz. ; this operation is performed on a slab or board previously 
moistened with water or expressed oil of almond ; these sticks or 
rolls should be wrapped in wax- or paraffin-paper to protect them 
from the air. 

Although, with two exceptions, the term plaster is officially applied 
to the mass or combination to be spread upon leather or muslin, it is 
more extensively used in trade to designate the finished spread plas- 
ter, ready for application. The spreading of plasters has almost 
entirely passed out of the hands of the pharmacists, hence it does not 
now appear necessary to describe and illustrate the various appliances 
which, 20 or 25 years ago, were considered a very essential and im- 
portant part of every educated pharmacist's outfit. Plaster masses, 
official and otherwise, can now be purchased of reliable quality, 
spread on muslin or other material, in one- and five-yard rolls, or in 
definite and convenient sizes, from large manufacturers, and there is 
to-day no more reason why a pharmacist should be compelled to make 
and spread his own belladonna plasters than that he should return to 
the spreading of his own adhesive plaster, as was done years ago. 
Moreover, plasters are prescribed but rarely now by physicians, and, 
when some new combination is ordered, the pharmacist will probably 
have little difficulty in spreading the plaster of fair quality and ap- 
pearance by following a few general directions here given. 

For extemporaneously spread plasters the best material is soft 
white leather, the kind known in the trade as plaster skin. A piece 
should be cut one inch larger each way than the size of the plaster 
ordered ; thus a 4 x 6 plaster would require a piece of leather 5x7 
inches ; now prepare four strips, one-half inch in width, of stiff 
paper, preferably glazed, and having previously prepared the plaster 
mass on a water-bath, as directed above, apply the paper strips to the 
rough side of the plaster skin in such a manner that the desired space 
shall remain uncovered, and carefully pour the melted plaster on the 



PLASTERS AXI) SUPPOSITORIES. 



387 



leather, smoothing the surface with a warm spatula, or by holding 
the spread plaster near a stove or furnace-register and allowing the 
soft material to run smooth. Then, having placed the spread plaster 
on a level surface, with a quick motion remove the paper strips before 
the plaster surface hardens, so that a clean half-inch margin around 
the plaster proper may be obtained. In place of a spatula, the little 
roller shown in 'Fig. 251 may be used with advantage for smoothing 

Fig. 251. 




Plaster-roller. 

the spread plaster mass ; it should be dipped in hot water, so as to 
become warm, before it is used, and then be moistened with a mix- 
ture of one volume of glycerin and two volumes of water to prevent 
adhesion. 

If the paper strips be attached before the melted mass is ready to 
be applied, the paste is apt to dry out, when subsequent removal of 
the paper from the rough leather becomes difficult, and hence some 
pharmacists prefer to moisten the strips with a damp sponge just 
previous to spreading the plaster mass ; this plan has been found 
very advantageous. Instead of using paper strips, some prefer to 
cut a frame of thin cardboard, with a ceutral opening of the required 
shape and size of the plaster, which is tacked clown on the plaster 
skin. The amount of material necessary for spreading a plaster of 
the required thickness need not exceed 12 or 15 grains for each 
square inch, or about 0.165 Gm. for each square centimeter. Plaster- 
spreading requires manipulative skill, and practice alone can bring 
success ; yet the writer has seen some plasters spread by students in 
his laboratory, who had never before seen the operation, that would 
have been a credit to any first-class pharmacy. 

Mammary or breast plasters are always made circular in form, 
about 8 inches in diameter, with a 1-inch margin ; a hole 1 J inches 



388 PRACTICAL PHARMACY. 

in diameter is cut in the centre, and from this point to the outer edge 
the plaster is slit to admit a folding over the breast. Such plasters 
are preferably spread on chamois skin, which is softer. 

Porous-plasters, which have become very popular, differ from ordi- 
nary spread plasters in having numerous small holes puuched through 
them, rendering them more comfortable for prolonged application, by 
allowing exhalations of the skin to pass off freely. They are pre- 
pared on an extensive scale by special machinery. 

Fly-plaster is the name frequently applied to cantharides or blis- 
tering cerate when the same has been spread upon adhesive plaster 
ready for use. The spreading of the cerate is done in the manner 
already outlined for regular plaster masses, except that heat is unnec- 
essary, since the cerate is sufficiently soft to permit of being spread 
by simple pressure of a spatula ; on cold winter days the spatula may 
be somewhat warmed with advantage. The amount of blistering 
cerate necessary for a given space should not exceed 10 or 12 grains 
for each square inch, or about 0.120 Gm. for every square centimeter. 
As fly-plasters are not intended for prolonged application, ordinary 
muslin or adhesive plaster will answer on which to spread the 
cerate, the latter material being preferable on account of the adhesive 
edges, which serve to keep the plaster from slipping about. A piece 
of tarletan, a trifle larger than the surface of the cerate, should be 
firmly pressed over the same, which, while not interfering with the 
blistering action of the cantharides, protects the skin from being 
much soiled, and prevents any of the cerate from getting under the 
skin if the blistered surface should be lacerated by sudden removal 
of the plaster. 

The Pharmacopoeia still recognizes 11 plaster masses and 2 spread 
plasters, very few of which, however, are used by physicians at the 
present day, except court and adhesive plasters for surgical purposes, 
and possibly belladonna plaster for its anodyne effect. The official 
directions for preparing the various plasters are explicit, requiring 
little or no additional remarks ; with care and observance of the pre- 
cautions before stated, good results will be obtained. 

Lead plaster is, strictly speaking, a chemical compound — lead oleate 
or lead soap — the manufacture of which will be more fully explained 
in connection with the subject of saponification. It enters either 
directly or indirectly into the composition of all but three of the 
official plasters. 

The proportions of ammoniac and lead plaster present in the offi- 
cial ammoniac plaster with mercury will vary, depending entirely 
upon the character of the gum-resin, which is frequently found in 
commerce of very indifferent quality, mixed with dirt and other 
foreign matter. 

The following is a list of the pharmacopoeial plasters showing 
their composition : 



PLASTERS AND SUPPOSITORIES. 



389 



Plaster Masses. 



Name. 

Emplastruni : 

Ainnioniaci cum Hydrar- 
gyro . 

Arnica? . 
Belladonna? 



Ferri 



Hydrargyri 



Opii 



Picis Burgundicse 

Picis Cantharidatum . 
(Warming Plaster. 

Plumbi 

Resinae 

(Adhesive Plaster. 

Saponis 



Composition of 100 parts 
Ammoniac ... 
Mercury 

Oleate of Mercury 
Diluted Acetic Acid 
Lead Plaster . 

Extract of Arnica Root 
Resin Plaster 

Extract of Belladonna Leaves 
Resin Plaster 
Soap Plaster . 

Ferric Hvdrate, dried . 
Olive Oif 
Burgundy Pitch ' . 
Lead Plaster . 

Mercury 

Oleate of Mercury 

Lead Plaster . 

Extract of Opium 
Burgundy Pitch . 
Lead Plaster . 

Burgundy Pitch . 
Olive Oil 
Yellow Wax . 

Cerate of Cantharides . 
Burgundy Pitch . 

Lead Oleate . 

Resin .... 
Lead Plaster . 
Yellow Wax . 

Soap, dried . 
Lead Plaster . 



(R 



? 72 parts. 

18 " 

0.8 " 



33 parts. 
67 " 

20 parts. 
40 " 
40 " 

9 parts. 
5 " 
14 " 

72 " 

30 parts. 
1.2 " 



6 parts. 

18 " 
76 " 

80 parts. 

5 " 
15 " 

8 parts. 
92 " 

100 parts. 

14 parts. 
80 " 

6 " 

10 parts. 
90 " 



Spread Plasters. 



Capsici. 
Ichthyocollse. 

Capsicum and isinglass or court plasters are the only plasters offi- 
cially directed to be spread, the former on muslin and the latter on 
taffeta. The body of the capsicum plaster is the official resin plaster, 
the surface of which is brushed over with oleo-resin of capsicum, 
0.25 Gm. being contained in every space 10 centimeters square, or 
about \ grain in every square inch. The material to be used in 
making court plaster is a mixture of gelatin 5 parts, water 60 parts, 
alcohol 40 parts, and glycerin 1 part ; it is applied to the taffeta after 
the surface has been painted with sizing. A coating of tincture of 
benzoin is afterward applied to the back to render the plaster water- 
proof. 

Suppositories. 

Suppositories are solid, medicinal preparations designed to be intro- 
duced into the rectum, vagina, urethra, or nose ; when intended for 



390 



PRACTICAL PHARMACY. 



the two last-named, they are usually termed bougies. They are of 
such consistence that, while retaining their shape at ordinary tem- 
peratures, they will slowly melt at that of the body or liquefy in the 
presence of moisture. The usual shape of rectal suppositories is that 
of a cone with a rounded apex (see Figs. 252 and 253), but the diffi- 



Fig. 252. 



Fig. 253. 



Fig. 254. 






Rectal suppositories. 
(For adults.) 



Rectal suppositories. 
(For children.) 



The Wellcome-shape 
suppository. 



culty of readily introducing these into the rectum, on account of the 
resistance offered by contraction of the sphincter muscle, has led to the 
suggestion of a new shape by H. S. Wellcome, of London, as shown in 
Fig. 254, the great advantages of which become apparent when it is re- 
membered that the bulbous end is inserted into the rectum first, and 
that as soon as the greatest diameter, which is about one-half inch 
from the point, has been passed, expulsion of the suppository is im- 
possible, by reason of the very contractile force of the sphincter, which 
renders retention of the ordinary conical shape often so difficult. 



Fig. 255. 



Fig. 2 



Fig. 257. 





Vaginal suppositories. 
Fig. 258. 



Urethral bougie. 



PLASTERS AND SUPPOSITORIES. 391 

Vaginal suppositories are made either globular or similar to the 
rectal suppositories, as shown in Figs. 255, 256, and 257, while, for 
urethral and nasal bougies, the pencil-shape, seen in Figs. 258, 259, 

Fig. 259. 



The Wellcome-shape urethral bougie. 

and 260, has been adopted, the last-named being about one-third as 
long, but twice as thick as the urethral bougies. 

Fig. 260. 



Nasal bougies. 

Suppositories are intended to insure a slow and uniform diffusion 
of their medicinal constituents to those internal parts to which they 
may be applied, and the choice of vehicle is made accordingly. The 
best substance for the preparation of suppositories is undoubtedly 
cacao- butter, or oil of theobroma, on account of its low fusing-point 
and bland, non-irritating properties. A mixture of glycerin and 
gelatin, known as glycerin-jelly, is also frequently employed, being 
particularly desirable for vaginal suppositories and nasal and 
urethral bougies, on account of its ready miscibility with water. 
It is admirably adapted for the exhibition of solid extracts, as 
those of opium, belladonna, and ergot, and such substances as chloral 
hydrate, but cannot be used in connection with tannic acid, owing to 
the fact that tannic acid combines with gelatin, forming an insoluble 
compound. The proportions best adapted for general purposes are 
gelatin 20 parts, glycerin 40 parts, and water 80 parts, the whole to 
be reduced by evaporation to 100 parts. For some purposes, these 
proportions may have to be changed ; thus, for hygroscopic drugs, 
such as potassium or sodium iodide and bromide^ chloral hydrate, 
etc., a mixture of gelatin 10 parts, water 40 parts, and glycerin 15 
parts, evaporated to 25 parts, will be found much better. Glycerin- 
jelly is prepared by soaking the gelatin in the water for a few hours, 
or oyer night, in a covered dish, then adding the glycerin and evap- 
orating on a water-bath to the required weight. 

In Great Britain a mixture of curd soap (soap made with animal 
fat) and glycerite of starch is frequently employed as a vehicle, made 
in the proportion of 30 parts of the glycerite to 100 parts of soap, 
sufficient powdered starch being added to make a stiff paste. 

The Pharmacopoeia recommends the weight of rectal suppositories 



392 PRACTICAL PHARMACY. 

to be about 1 gramme (15 grains), of vaginal suppositories about 3 
grammes (45 grains), and of urethral bougies about 1 gramme (15 
grains), but these sizes are frequently exceeded in practice to 2 or 3 
times the above specified weights. 

Since suppositories are, like ointments, simply mechanical admix- 
tures of the medicinal constituents and a vehicle, the former must 
always be incorporated in the form of an impalpably fine powder or 
in a state of solution, solid extracts being rubbed into a smooth paste 
with water. On account of the peculiar application of suppositories, 
it is important that no coarse or gritty particles should ever be con- 
tained therein. They are made either entirely by hand, by casting 
in appropriate moulds, or by cold compression in suitable apparatus. 

Hand- made suppositories are, as a rule, not so exact and uniform 
in shape as those moulded, although some pharmacists have attained 
considerable perfection and dexterity in following this convenient 
method. The usual plan is to effect an intimate mixture of the 
active ingredients and vehicle in a mortar, by forming them into a 
uniform mass, and transfer the mass to a graduated tile to be divided 
into the required number of equal parts, which are then properly 
shaped with the fingers. To prevent adhesion of the mass to the tile 
or fingers, it may be dusted with some finely powdered starch or a 
mixture of starch and lycopodium. This method, of course, excludes 
the use of glycerin-jelly, and, if the mass shows a disposition to 
crumble, the addition of a few drops of castor oil will overcome the 
difficulty, rendering the mass plastic. One of the best vehicles for 
making suppositories by hand, or by cold compression, is a mixture 
of cacao-butter 5 parts, castor oil 1 part, and yellow wax 1 part, 
which fuses at about the same temperature as cacao-butter. 

For casting suppositories in moulds it is necessary to have the 
mass in a fluid state. If carefully and skilfully followed, this 
method yields the most perfectly shaped and finished suppositories 
that can be made ; but it requires practice to insure success, present- 
ing more difficulties than any other method. If the fluid mass be 
pcured into the moulds too warm, immediate separation of the in- 
soluble ingredients occurs, which settle in the apex of the cone. If 
allowed to cool too fast, it will not flow properly, and fill the moulds 
imperfectly ; the proper condition of the mass is reached when the 
fluid is of a thin, syrupy consistence and a slight film begins to form 
on the surface. High heat should be avoided in preparing the mass, 
a low, water-bath heat being amply sufficient for melting the cacao- 
butter or glycerin-jelly. Any solid extract to be added should be 
softened down with a little water, mixed with a small quantity of 
melted vehicle on a tile, and transferred to the dish or capsule con- 
taining the remainder of the melted vehicle, which has been removed 
from the water-bath and allowed to cool somewhat. By stirring 
with a glass rod or narrow steel spatula the extract will become 
uniformly incorporated, after which any solid ingredient, in very fine 
powder, may be added and thoroughly mixed ; the fluid mass is then 



PLASTERS AXD SUPPOSITORIES 



393 



immediately poured into well-chilled moulds, with constant stirring 
to prevent separation. It is important that no heat be applied to the 
mass after the addition of the medicinal constituents lest separation 
occur, particularly in the case of extracts, which cannot afterward be 
successfully overcome. The moulds must be perfectly clean and dry, 
having been previously well chilled by placing them on ice ; there 
will then be no occasion whatever for dusting them with lycopodium 
or other substance. If the fluid mass is of the right consistence and 
the mould cold, it will immediately congeal and contract on being 
poured into the moulds, but sufficient time should be allowed for the 
suppository to harden throughout, otherwise some trouble may be 
experienced in removing them ; in winter twenty or thirty minutes 
will suffice, whereas forty minutes or longer may be necessary in 
summer unless the mould, after having been filled, be placed in an 
ice-chest. Various styles of moulds are in use among pharmacists, 
those known as divided moulds, opening either horizontally or verti- 
cally, being preferred on account of the convenience with which they 
can be taken apart and cleaned. Figs. 261, 262, 263, and 264 rep- 
resent four different styles of moulds, from all of which the supposi- 
tories can be quickly removed by bearing slightly with the finger 
agaiust the conical ends after the moulds have been opened. 

Fig. 261. 




closed 



open. 



Maris' suppository mould. 
Fig. 262 




Wirz's suppository mould (open). 



The numerous difficulties attending the casting process have led 
many pharmacists to abandon this process in favor of cold compres- 
sion. The chief advantages of the compression method are the 
saving of time, and the absence of all danger of overheating and of 
separation of extracts and other ingredients, while the suppositories 
are uniform in composition and leave nothing to desire in appear- 
ance, although the finish is possibly not quite so perfect as in care- 



394 



PRACTICAL PHARMACY. 



fully-cast suppositories. The mass for compression is prepared in a 
mortar, as forehand-made suppositories, and, when a uniform mixture 
has been obtained, it is removed and cut up into small pieces, which 
are placed in the hopper or barrel of the compressor. 



Fig. 263. 




See's suppository mould. 



Fig. 265. 



Fig. 264. 





Blackman's suppository mould. 



The Archibald suppository machine. 

The first successful compression mould for dispensing purposes was 
that known as the Archibald mould (see Fig. 265), which is still used 
by many. The only objection to this mould is the tedious removal 
of the finished suppository ; the adhesion of the mass to the sides 
can be readily overcome, however, by swabbing the mould with a 
pledget of cotton dampened with glycerin between every two com- 
pressions. 

The two apparatuses shown in Figs. 266 and 267 are improve- 
ments on the Archibald mould in so far that 3 rectal suppositories 
can be compressed at once, whilst the finished product is easily and 
quickly removed. They differ from each other only in the position 



PL AS TEES AND SUPPOSITORIES. 



395 



of the compressor, one being perpendicular and the other horizontal; 
both, however, require considerable effort to force the mass through 



a, closed. 



Fig. 206. 



b, open. 





The " Perfection " suppository mould, 



the small openiugs in the top of the moulds into the moulds proper 
underneath, which is the only objection that can be urged against them. 



Fig. 267. 




Whitall's suppository machine. 

Each of the three compression machines is provided with a set of 3 sup- 
pository moulds (2 rectal, 30 and 15 grains, aud 1 vaginal) and 1 



396 



PRACTICAL PHARMACY. 



bougie mould. In the Archibald machine the moulds are placed 
in a swinging bed, which is secured under the cylinder by means of a 
lever, and after the suppository has been compressed the swinging 
bed is loosened, the mould taken out and opened, and the suppository 
removed by gently pushing it with the thumb. In the two other 
machines the moulds are screwed into the lower part of the cylinder, 
resting firmly against an iron bed-plate; to remove the compressed 
suppository it is only necessary to open the bed-plate, as shown in 
Fig. 266, a, and, by one or two turns of the screw, push the suppos- 
itories out of the moulds. For the compression of nasal or urethral 
bougies a plate is put into the cylinder and a small tube attached, 
through which the mass can be forced to any desired length. 



Fig. 268. 




The Genese suppository compressor. 



For cold compression of the Wellcome-shape suppositories a ma- 
chine has recently been perfected which is easily filled and operated, 
and produces excellent results. The suppositories are compressed in 
paper shells, which permit of their ready removal from the moulds 
and avoid all contact with the fingers. The mode of filling the 
moulds, as seen in Fig. 268, is entirely different from that of other 
compression machines ; the mass, being first carried from the cylinder 
to the point of the mould, then fills the paper shell perfectly and 
compactly, as the mould is made to recede under the influence of the 
pressure from the cylinder. As the moulds come in sets of four or 
six attached to a plate, the suppositories can be made very rapidly 
with this machine. In Fig. 269 is shown the cylinder swung back, 
with the cap removed, for the purpose of filling it with the material 
to be compressed. 

Bougies, made with glycerin-jelly, are cast in special moulds, such 



PLASTERS AND SUPPOSITORIES. 
Fig. 269. 



397 




The Genese suppository compressor, open. 



as are shown in Figs. 270 and 271 ; the tubes are usually swabbed with 
a woollen rag carrying some liquid petrolatum or olive oil, to prevent 



Fig. 270. 




Mould for gelatin bougies. 
Fig. 271. 




Mitchell's urethral bougie mould. 



398 PRACTICAL PHARMACY. 

adhesion of the material. When made with cacao-butter or soap and 
starch, they can be either compressed or formed by hand. Nasal 
bougies should be about 38 millimeters (1 J inches) in length and 
6 millimeters (J inch) in diameter, while urethral bougies are usually 
made 100 millimeters (4 inches) in length and from 3 to 4 milli- 
meters (\ to \ inch) in diameter. The ends of both are somewhat 
pointed, as shown in Fig. 258. 

The Pharmacopoeia recognizes only one special kind of supposi- 
tories, viz., those of glycerin, and gives general directions for the 
preparation of all others. Glycerin suppositories are composed of 
90 per cent, of glycerin and 10 per cent, of sodium stearate. In the 
official formula, crystallized sodium carbonate is dissolved in glycerin, 
on a water-bath, after which stearic acid is added and the heat con- 
tinued until effervescence ceases, when the solution is poured into 
moulds and allowed to congeal. The three grammes of sodium car- 
bonate used will yield 6.4 grammes of sodium stearate, according 
to the equation 2HC 18 H 35 2 + Ea 2 CO 3 10H 2 O = 2NaC 18 H 35 2 -f- 
11H 2 -f- C0 2 , which is sufficient to form a solid mass with 60 
grammes of glycerin, the water aud carbon dioxide being dissipated. 
Owing to the very hygroscopic nature of glycerin, the suppositories 
must be either wrapped in tinfoil or dispensed in small straight vials 
without a lip ; some manufacturers coat them by dipping them into 
melted paraffin, which protects them against the air, but has the dis- 
advantage of possibly failing to be removed by the patient before 
insertion, in which event the suppository could not act, as the heat of 
the body is not sufficient to melt paraffin. 

A very ingenious apparatus has been devised by Dr. Genese, of 
Baltimore, for the purpose of casting glycerin suppositories of the 
" Wellcome " shape in pure tinfoil shells, which can be quickly and 
hermetically sealed, and thus all contact with the hands and air be 
avoided. The apparatus and mode of using it are illustrated in Fig. 
272. A is a tin or copper boiler of about one-pint capacity, with 
handle attached. The top is extended into a double-wall cylinder, B, 
open to a certain width on one side for its entire length, and serving 
as a steam or hot- water jacket ; it is provided with a steam-vent at C 
and a safety-valve at D, through which the boiler can also be re- 
plenished with water, when necessary. E is a heavy glass (or metal) 
cylinder in which the glycerin mass is to be prepared and kept ; it 
fits snugly into the jacket, B, and is provided near the bottom with 
a small spigot for feeding the melted mass into the tinfoil shells pre- 
viously arranged in the moulds. When not in use the cylinder, E, 
can be covered with a ground-glass plate or closed with a rubber 
stopper, by which arrangement a supply of the mass can be kept on 
hand, requiring only slight heating to liquefy it when suppositories 
are to be cast. 

Where glycerin suppositories are frequently sold, this apparatus 
will prove a most desirable addition to the appliances for rapid and 



PLASTERS AND SUPPOSITORIES. 



399 



neat dispensing, and, being always ready for use, will save much 
labor and annoyance. 

Fig. 272. 




Apparatus for making glycerin suppositories of the " Wellcome" shape. 

In Fig. 273 is shown a little device for sealing the edges of the 
tinfoil shells, which can be made of either metal or rubber. The 
construction is such that, when the shell containing the solidified 
glycerin mass has beeu placed in the lower section, A, and the upper 
section, B, is brought down over it with a little pressure, the project- 
ing lateral edges of the shell (see Fig. 274) are folded by means of 
the grooves ; by then reversing the shell, a secoud fold is tightly 
creased in the same manner, and all air thus excluded. The shells 
being filled only to within about T 3 g- of an inch of the mouth, the pro- 
jecting front edges can be lapped over before the lateral edges are 
folded, and thus the whole shell be hermetically sealed. Fig. 275 
represents one of the tinfoil shells filled and sealed ; glycerin suppos- 
itories thus preserved have been found to keep excellently in ordinary 
boxes, during hot weather, and upon removal from the shells were 
found firm and free from moisture. 

Suppository shells made of gelatin or butter of cacao have been 
introduced for the convenience of the dispenser, but are not used to 



PRACTICAL PHARMACY. 




Glycerin suppository in tinfoil shell ; 



Apparatus for sealing tinfoil sup- 
pository shells. 



any extent. The medicinal ingredient is intended to become mixed 
with the material of the shells as the latter melts, but, as this is un- 
certain, they should never be used in case the direct application of 



Fig. 276. 



0066 




Suppository shells, made of cacao-butter. 



Fig. 277. 



I III 



Of _i 

j 9 



Gelatin suppository shells. 



the active agent might irritate ; for the introduction of boric [acid, 
iodoform, aristol, etc., they are, however, well adapted. In the case 
of butter of cacao shells (see Fig. 276) they are preferably filled with 



PL AS TEES AND SUPPOSITORIES. 



401 



a mixture of the active ingredient and grated butter of cacao, and 
the top sealed either with a warm spatula or a little stiff mucilage of 
acacia. The gelatin shells, see Fig. 277, may be conveniently sealed 
by moistening the margin of the lower half with a little water, 
before slipping the upper part over the same. The best method of 
dispensing suppositories is undoubtedly in partition paper boxes (see 
Fig. 278), the sides aud bottom of which should be lined with tinfoil 



Fig. 278. 




Suppository box. 



or paraffin paper, the patient always being directed to keep the box 
in a cool place; in the absence of partitioned boxes, an oblong 
powder box may be used, the suppositories being placed between two 
pieces of sheet-wadding. 



26 



PART III. 

PHARMACEUTICAL CHEMISTRY. 



Although the term pharmaceutical chemistry is objected to by 
many who rightfully claim that there can be bat one kind of chem- 
istry, the laws and principles of which must be the same whether 
applied to pharmacy, medicine, physiology, or agriculture, it will, 
nevertheless, be retained in this book as a convenient heading under 
which to group the many details of composition, preparation, and 
examination of that vast number of chemical compounds in almost 
daily use by pharmacists, and the majority of which are officially 
recognized in the U. S. Pharmacopoeia. The classification of chem- 
ical compounds with regard to constitution, etc., will, in the main, 
not be based upon the views at present accepted by chemists, con- 
cerning which the student of pharmacy receives ample iustruction in 
his chemical lectures, and of which he can find full explanation in 
the many excellent chemical text-books of to-day ; but a somewhat 
unsystematic arrangement will be followed, having in view more par- 
ticularly the study of official and other chemicals from a pharmaceu- 
tical standpoint, irrespective of their chemical relationship. After 
an experience of many years this plan, being still found the most 
desirable for pharmacists, is adhered to in pharmaceutical schools. 

Chemical compounds may be conveniently divided into those 
usually designated as inorganic substances and those formerly known 
as organic compounds, but to which, now, the name carbon com- 
pounds is more appropriately applied. 

Inorganic Substances. 

Of the thirteen elements which are known as non-metallic bodies, 
all but four are of pharmaceutical interest, either because they are 
employed extensively by physicians in their elementary state or be- 
cause they form certain important compounds with each other which 
are officially recognized in the Pharmacopoeia ; such compounds only 
will be considered here, and these are furnished by the following 
elements : hydrogen, oxygen, chlorine, bromine, iodine, sulphur, 
phosphorus, carbon, and boron. A very valuable class of com- 



404 PHARMACEUTICAL CHEMISTRY. 

pounds formed by these elements are the inorganic acids, which will 
be treated in a special chapter. 

Combinations of non- metallic elements with the metals are very 
properly classified as compounds of the latter, and will be treated in 
connection with the salts and numerous other preparations of the 
metals, officially recognized. The compounds of metals may be con- 
veniently considered according to a system of division which groups 
those metals together the oxides of which possess certain well- 
recognized properties in common ; thus, metals of the alkalies, of the 
alkaline earths, of the earths and heavy metals. 

Since very few metallic salts are prepared by pharmacists, such 
compounds will be treated chiefly with a view of enabling the student 
to understand fully the official requirements as regards identity and 
quality, detailed consideration being given mainly to those com- 
pounds for the preparation of which the Pharmacopoeia gives official 
working formulas. 



CHAPTEE XXXYI. 

HYDROGEN AND OXYGEN. 

Neither of these elements is of pharmaceutical value in its 
uncombined gaseous state, but they unite to form two very important 
compounds. 

The most important compound of hydrogen and oxygen is water, 
which may be looked upon chemically as hydrogen monoxide, H 2 0, 
and has already been referred to on page 206. The Pharmacopoeia 
recognizes both natural and distilled water, and, while in some local- 
ities, natural water may be obtained remarkably free from impurities, 
the use of distilled water is to be preferred at the dispensing counter 
and for the preparation of aromatic waters and many chemical solu- 
tions. Distilled water is required to be absolutely free from both 
inorganic and organic impurities, while the official limit of the former 
in natural water is indicated by a residue not exceeding 0.5 Gm. of 
inorganic salts upon evaporation of 1000 Cc. of water. Natural 
water mixed with 10 per cent, of its volume of diluted sulphuric 
acid and \ per cent, of deci-normal potassium permanganate solution, 
should not become completely decolorized by boiling it for 10 min- 
utes, showing the pharmacopceial limit of organic and other oxidiz- 
able matters. 

Hydrogen dioxide, H 2 2 , first obtained in 1818 by Thenard, con- 
tains 94 per cent, of oxygen, and is the richest oxygen compound 
known. It is officially recognized, in the form of a 3 per cent, 
aqueous solution, under the name Aqua Hydrogenii Dioxidi. 

The compound H 2 2 may be obtained from any metallic dioxide 
which yields a portion of its oxygen to water, upon treatment with 
an acid. For technical purposes sodium dioxide is extensively em- 
ployed, but this method is not suitable for medicinal purposes, as the 
resulting solution cannot be freed from the accompanying sodium 
sulphate or chloride; hence the Pharmacopoeia directs that the official 
solution shall be made from barium dioxide, which, upon saturation 
with an acid, readily gives up one-half of its oxygen to water to form 
hydrogen dioxide. 

An important step in the official process is the thorough hydration 
of the barium dioxide, in order to insure rapid and complete satura- 
tion subsequently with the acid ; experience has shown that cold 
favors the hydration of the finely powdered barium dioxide, which 
is known to be completed when the water separates but slightly 
from the resultiug magma. Phosphoric acid has been found to pro- 
duce a better yield of H 2 2 than sulphuric or carbonic acid, and is 



406 PHARMACEUTICAL CHEMISTRY. 

even preferable to hydrochloric acid, owing to the practical difficulty 
of removing the free acid after decomposition of the barium chloride 
formed. Hydrofluoric acid has also been successfully employed for 
the liberation of hydrogen dioxide, but its corrosive nature presents 
great obstacles to its use, although the resulting barium fluoride is 
even more insoluble than the phosphate. The hydrated barium 
dioxide must be fully decomposed, and saturated with acid to exact 
neutrality ; hence the Pharmacopoeia directs that a portion of the 
well-cooled diluted phosphoric acid be set aside as a reserve, and 
used, in small quantities, after all the barium dioxide mixture has 
been added to the remainder of the acid, until a perfectly neutral reac- 
tion is obtained. Vigorous agitation and refrigeration of the acid 
and barium mixture are necessary to insure a full yield of H 2 2 . 
The addition of small quantities of diluted sulphuric acid to the 
filtered solution is for the purpose of freeing it entirely from barium, 
a small portion of which will have entered into solution as acid 
barium phosphate ; the subsequent removal of the finely precipitated 
barium sulphate is greatly facilitated by the admixture of a little 
starch before filtration. The finished product contains a small 
amount of phosphoric acid, liberated from the acid phosphate, which 
materially aids in the preservation of the solution ; a trace of sul- 
phuric acid is also present, as it is impossible to avoid adding a slight 
excess. 

Solution of hydrogen dioxide readily undergoes spontaneous de- 
composition, particularly if exposed to heat and sunlight ; it should, 
therefore, be preserved in a cool, dark place, or in amber-colored 
bottles, which have been loosely stoppered to avoid explosion in case 
of defective bottles and increased pressure caused by accumulation of 
gas. As a preservative, boro-glycerin has been suggested, and, when 
used in the proportion of 1 part in 100 of the solution, has been found 
serviceable in retarding the rate of decomposition. Moderate heat is 
far less injurious than daylight, and Dr. Squibb has found that, if a 
temperature of 60° C. (140° F.) be not exceeded, a fifty-volume solu- 
tion can readily be obtained by concentration on a water-bath, without 
appreciable loss of dioxide; above this temperature, however, decom- 
position rapidly increases. 

The Pharmacopoeia requires that solution of hydrogen dioxide 
shall contain 3 per cent, by weight of the pure dioxide, which corre- 
sponds to about 10 volumes of available oxygen. The assay is made 
with potassium permanganate, in the presence of sulphuric acid, ac- 
cording to the reaction 5H 2 2 + 3H 2 S0 4 + 2KMn0 4 = K 2 S0 4 + 
2MnS0 4 + 8H 2 -f- 50 2 . Only one-half of the oxygen indicated 
in the equation is derived from the hydrogen dioxide, the other half 
being furnished by the potassium permanganate, which fact must be 
considered if the gas is collected and measured in a gas-tube over 
mercury. The term available oxygen refers, therefore, to the volume 
of nascent oxygen obtained directly from the dioxide, and not to the 
total volume liberated in the reaction. From the above equation it 



HYDROGEN AND OXYGEN. 407 

is seen that two molecules (315.34 parts) of potassium permanganate 
correspond to five molecules (169.60 parts) of hydrogen dioxide; 
hence each Cc. of a decinormal solution of the former containing 
0.0031534 Gra. of KMn0 4 must be equivalent to 0.001696 Gm. of 
H 2 2 , or 0.000798 Gm. of oxygen available therefrom. 

Thus the volume strength of any solution of hydrogen dioxide 
can be conveniently calculated, simultaneously with the percentage 
strength, without the necessity of collecting and measuring the actual 
gas volume, by reckoning the weight of one cubic centimeter of 
oxygen at 0° C. and 760 Mm. atmospheric pressure as equivalent to 
0.00143 Gm. (actually 0.001424488); then, dividing the weight of 
oxygen equivalent to 1 Cc. of f^- KMn0 4 solution by 0.00143, we 
shall obtain 0.56 Cc. (actually 0.5594) as the volume of oxygen rep- 
resented by each cubic centimeter, and multiplying the number of 
Cc. -yq KMn0 4 solution decolorized by 1 Cc. of H 2 2 solution by 
0.56, the volumes of available oxygen are indicated by the product. 
Multiplying, at the same time, the number of Cc. y^- KMn0 4 solution 
so decolorized by 0.17 (actually 0.1696 = 0.001696 X 100) will 
yield the percentage by weight of absolute H 2 2 . 

The reaction with potassium chromate and ether mentioned in the 
Pharmacopoeia depends upon the formation of a new compound 
which forms a blue solution with ether ; it is characteristic of 
hydrogen dioxide. By some the compound formed is considered to 
be perchromic anhydride (Cr 2 7 ), a substance analogous to perman- 
ganic anhydride (Mn 2 7 ), while others assume that it may possibly be 
a compound of CrO a and H 2 2 . 



CHAPTEE XXXVII. 

CHLOKINE, BKOMINE, AND IODINE. 

Chlorine is used by physicians, in its elementary state, in the 
form of an aqueous solution, which the Pharmacopoeia recognizes 
under the name of Aqua Chlori, and for the preparation of which 
an official formula is given. 

When manganese dioxide is treated with hydrochloric acid the 
oxygen which is liberated does not unite with water to form hydro- 
gen dioxide, as in the case of barium and sodium dioxides, but unites 
with the hydrogen of the hydrochloric acid to form water ; the chlo- 
rine being thus set free, a portiou combines with the manganese, 
while the remainder passes off in gaseous form, according to the 
following equation : Mn0 2 + 4HC1 = MnCl 2 + Cl 2 -f 2H 2 0. The 
manganese dioxide used should be free from fine particles, in pieces 
of about the size of small filberts, and used in such quantity that it 
is not completely covered by the acid liquid ; this insures a slow but 
regular disengagement of chlorine gas and diminishes the loss of 
acid vapors. Chlorine may also be conveniently evolved from a 
mixture of sodium chloride, manganese dioxide, and sulphuric acid 
somewhat diluted with water, sodium chloride yielding over 60 per 
cent, of its w 7 eight of chlorine, the reaction being the following : 
2NaCl + Mn0 2 + 2 H 2 S0 4 = Na 2 S0 4 + MnS0 4 + 2H 2 + Cl 2 . 

Since cold favors the solution of gases in water, it is desirable that 
the water into which the chlorine is conducted be kept at a tempera- 
ture not above 10° C. (50° F.), at which temperature water absorbs 
about three times its volume of chlorine gas. The receiving vessel 
should be shaken from time to time, as long as absorption takes place, 
which is shown by the stopper being drawn in after agitation, in 
order that a saturated solution may be obtained. The washing of 
the gas, directed in the official process, is for the purpose of elimin- 
ating any hydrochloric acid vapor which may have passed over with 
the chlorine. 

When preparing chlorine water, sulphurous acid, and similar 
solutions it may happen that, owing to cessation or interruption of 
the gas-flow, a partial vacuum is produced in the generating flask, 
and, as a consequence, liquid from the wash-bottle is drawn over 
into the flask, and, coming in contact with the heated glass, will 
cause a fracture. This may be avoided either by using a safety- 
tube or by disconnecting the flask from the wash-bottle as soon as 
gas- bubbles cease to pass over. 

Chlorine water is very unstable, and must be preserved in small, 



CHLOBIXE, BROMINE, AND IODISE. 409 

completely -filled vials, securely stoppered and paraffined, in a cool 
dark place, otherwise chlorine will escape and the formation of 
hydrochloric acid rapidly set in. It is one of those preparations 
requiring the pharmacist's special attention, for, when prescribed by 
physicians, it is wanted of full strength, which is not possible if the 
solution be carelessly preserved in partly-filled bottles or exposed to 
daylight. 

The strength of chlorine water, required by the Pharmacopoeia to 
be ^q- of 1 per cent, by weight of chlorine, can be ascertained by 
decomposing a solution of potassium iodide by means of the chlorine 
water and volumetrically determining the amount of iodiue thus set 
free. Chlorine always displaces iodine in atomic proportions, and, 
in the official assay the following reaction takes place : 2KI + Cl 2 
= 2KC1 -f I 2 , 70.74 parts of chlorine liberating 253.06 parts of 
iodine ; therefore, 17.7 Gm. of chlorine water, containing 0.0708 Gm. 
of chlorine (0.4 per cent, of 17.7), would liberate 0.25306 Gm. of 
iodine, which is held in solution by an excess of potassium iodide. 
The actual amount of iodine set free is determined with y^ sodium 
thiosulphate solution, of w T hich each Cc. will decolorize 0.012653 
Gm. of iodiue in solution, according to the following reaction : 
2(Xa 2 S 2 3 + 5H 2 0) + I ? = 2XaI + Xa 2 S 4 6 + 10H 2 O, sodium 
iodide and tetrathionate being formed, which both yield colorless solu- 
tions. Since 253.06 Gm. of iodine' are equal to 70.74 Gm. of chlorine, 
each Cc. of the ^ sodium thiosulphate solutiou will represent 0.003537 
Gm. of chlorine, and the number of Cc. necessary to decolorize the 
deep red liquid may be multiplied by 0.003537 to find the total 
amount of chlorine present — this multiplied by 100 and divided by 
the weight of chlorine water used indicates the percentage of chlorine. 

Bromixe is employed in its free state as an antiseptic and disin- 
fectant, and is occasionally used internally as an alterative. It is 
a heavy, dark brownish-red liquid, which, even at ordinary tempera- 
tures, evolves highly irritating vapor ; hence considerable care is 
necessary in handling bromine. A vial of bromine should be well 
cooled before opening, especially in warm weather, to avoid acci- 
dents, and, if large quantities are to be used, as in the manufacture 
of syrup of ferrous bromide and similar preparations, it is best to 
open the vial of bromine under ice water. Contact of bromine or 
its vapor with metallic surfaces must be carefully avoided. 

The manufacture of bromine has rapidly increased during the last 
thirty years, and immeuse quantities of it are now produced in this 
country. It occurs in nature, in aqueous solution, combined with 
sodium, magnesium, and calcium, and is present in sea-water to the 
extent of about T i-- of 1 per cent. The commercial sources of 
bromine are the mother-liquors left after the crystallization of 
sodium chloride at the salt wells of Ohio, Pennsylvania, West 
Virginia, and Michigan iu this country, and near Stassfurt, in Ger- 
many. Since the bromides are far more soluble than the chlorides, 



410 PHARMACEUTICAL CHEMISTRY. 

the former remain in solution in the mother-liquors, to which the 
name bittern is given in this country. The bittern is concentrated 
until a density of about 1.45 is reached, which facilitates the further 
removal of chlorides and sulphates, then transferred to stone-ware 
stills, where a mixture of sulphuric acid and manganese dioxide is 
added, which, with the aid of heat, liberates the bromine according 
to the following reaction : MgBr 2 + Mn0 2 + 2H 2 S0 4 = Br 2 + 
MgS0 4 -f- MnS0 4 + 2H 2 0. The bromine vapor is condensed in 
well-cooled receivers and freed from water by distillation over cal- 
cium chloride. 

It is difficult to obtain bromine entirely free from chlorine, the plan 
usually followed being distillation with a bromide, whereby the 
corresponding chloride is formed and bromine set free. The Phar- 
macopoeia permits the presence of 3 per cent, of chlorine, an excess 
being indicated by the formation of a precipitate, within three min- 
utes, upon addition of nitric acid to the filtrate obtained after pre- 
cipitation of 1 Cc. of saturated bromine water with 5 Cc. y^- silver 
nitrate solution in the presence of 3 Cc. of ammonium carbonate test- 
solutiou. This test depends upon the ready solubility of silver 
chloride and the sparing solubility of silver bromide in ammonium 
carbonate solution, and is approximately accurate. It has been 
observed that, if 1 per cent, of chlorine be present, the addition of 
nitric acid causes only a faint opalescence, but no precipitate, even 
in one hour's time ; 2 per cent, leaves the liquid perfectly trans- 
parent, but a white sediment is formed in thirty minutes ; 3 per 
cent, causes separation of white flocculi in three minutes, although 
the liquid remains transparent, while 4 per cent, causes turbidity and 
the immediate formation of a flocculent precipitate. To determine 
the exact amount of chlorine present, the best plan is to mix 1 Gm. 
of bromine with 10 Cc. of distilled water, adding sufficient ammonia 
water to produce a clear solution, then digest with barium carbonate, 
filter, evaporate the filtrate to dryness, and gently ignite the saline 
residue. The latter should be soluble in absolute alcohol, and every 
0.0294 Gm. of insoluble residue will indicate 1 per cent, of chlorine, 
barium chloride being insoluble, while the bromide is soluble in 
absolute alcohol. 

Bromoform and other organic impurities, which, in part at least, 
are derived from the luting and fastenings of the stills, may be 
present in bromine. Iodine is rarely present, but, if so, will be 
libeiated by ferric chloride, if the latter be added to a solution 
of bromine previously shaken with reduced iron until nearly color- 
less, and may be detected with the aid of starch ; the reaction is as 
follows : Fel 2 + Fe 2 Cl 6 = 3FeCl 2 -f I 2 . 

Bromine has been found au efficient antidote to the poison of the 
rattlesnake, and the following formula for Bibron's Antidote is taken 
from Parrish's Pharmacy, published in 1884 : Dissolve 5 drachms 
(300 grains) of bromine in 6 fluidounces of diluted alcohol and 4 
grains of potassium iodide and 2 grains of mercuric chloride in 1 J 



CHLOBIXE, BBOMIXE, AXE IODIXE. 41 1 

fluidounces of diluted alcohol ; mix the two solutions. Dose : 10 
drops in a tablespoonful of brandy, to be repeated as required. 

Iodine is more extensively employed in its elementary state than 
any other element, both internally and externally. It was formerly 
derived solely from the ashes of sea-plants, particularly of certain 
species of Laminaria. These ashes are known on the coast of Scot- 
land, where at one time the chief iodine manufactories were located, 
as kelp, in Norway as varec, and in Spain as barilla; they contain 
iodine in the form of alkali iodides, Nal and KI. After treatment 
with water, the chlorides, carbonates, and sulphates present are 
removed by evaporation of the solution and crystallization, sul- 
phuric acid is then added to decompose sulphides aud other sul- 
phur compounds ; to the acid liquid, manganese dioxide is added, 
and the mixture is heated. The iodine, volatilizing, passes into 
suitable condensing flasks and sublimes, a reaction similar to that 
stated under chlorine and bromine taking place. 

At present vast quantities of iodine are obtained in South America, 
from the mother-liquors of the so-called Chili saltpetre, sodium 
nitrate, which contains iodine in the form of sodium iodate. The 
iodine is obtained either by direct precipitation with sodium bisul- 
phite and sulphur dioxide or by sublimation, after addition of man- 
ganese dioxide and sulphuric acid to cuprous iodide, which has been 
previously precipitated from a solution of sodium iodide by cupric 
and ferrous sulphates. The chemical reactions involved in these 
two processes can be seen from the following equations : 

Bv direct precipitation : 
2XaIO s + 4XaHSO s + S0 2 = 4XaHS0 4 + Xa 2 S0 4 +I 2 . 

By sublimination, from cuprous iodide: 

1. NaI0 3 + 3NaHS0 3 = 3iS T aHS0 4 + Xal. 

2. 2XaI -j- 2CuS0 4 + 2FeS0 4 = Cu 2 I 2 + Na 2 S0 4 + Fe 2 (S0 4 ) 3 . 

3. Cu 2 I 2 + 2Mn0 2 + 4H 2 S0 4 = 2CuS0 4 + 2MnS0 4 + I 2 + 
4H 2 0. 

The crude iodine thus obtained is freed from moisture and purified 
by resublimation. Commercial iodine may contain, as impurities, 
cyanogen, chlorine, and bromine, present as CNI, IC1 3 , and IBr. 
The Pharmacopoeia demands the absence of iodine cyanide, which is 
a very poisonous compound, and limits the amount of chlorine and 
bromine. In the official test for iodine cyanide, a further addition 
of a drop of ferric chloride test-solution, made before adding the so- 
dium hydroxide solution, would render the reaction much sharper, 
as it depends upon the formation of ferric ferrocyanide, Fe 4 (FeC 6 X 6 ) 3 , 
which, if present in sufficient quantity, will settle as a blue precipi- 
tate, otherwise only a blue color is imparted to the liquid. The 
official limit-test for chlorine and bromine depends upon the greater 
solubility of silver chloride and bromide in ammonia water and their 
subsequent precipitation upon the addition of nitric acid. 

The Pharmacopoeia requires 98.85 per cent, purity in iodine, which 



412 PHARMACEUTICAL CHEMISTRY. 

is volumetrically determined with T \ sodium thiosulphate solution, 
each Cc. of which corresponds to 0.012653 Gm. of iodine. If 0.32 
Gm. of iodine be used for the valuation, as directed in the Pharma- 
copoeia, 25 Cc. of the -^ Na 2 S 2 3 solution will be required to de- 
colorize the liquid completely; for 98.85 per cent, of 0.32 is equal to 
0.31632, and 0.31632 divided by 0.012653 yields 25. The reaction 
involved in this test has already been explained under chlorine. 

One solid and two liquid preparations containing iodine in a free 
state are recognized in the Pharmacopoeia, namely, an alcoholic tinc- 
ture containing 7 Gm. of iodine in 100 Cc. ; an aqueous solution 
known as Lugol's solution, containing 5 per cent., by weight, of 
iodine held in solution by twice its weight of potassium iodide ; and 
an ointment containing 4 per cent., by weight, of iodine. The 
amount of iodine present in any sample of the tincture or compound 
solution can be readily determined by titration with sodium thio- 
sulphate, as directed in the Pharmacopoeia the addition of potas- 
sium iodide, in the valuation of tincture of iodine, is for the purpose 
of preventing the precipitation of iodine by the water. 

In the National Formulary three other liquid preparations of 
iodine are mentioned : Churchill's tincture of iodine, Churchill's 
iodine caustic, and decolorized tincture of iodine. The first two 
named should not be confounded with each other, as they differ 
greatly in strength, the tincture being of about one-half the strength 
of the caustic. Decolorized tincture of iodine is not a solution of 
iodine at all, the name being misapplied ; the finished colorless pro- 
duct contains sodium iodide, sodium tetrathiouate, and ammonium 
iodide formed by reaction between iodine, sodium thiosulphate, aud 
ammonia water. The preparation, in a short time, takes on a dis- 
agreeable alliaceous odor and deposits crystals of sodium tetrathiouate, 
which may be removed by filtration. 

Iodine forms with hydrogen an important although rather unstable 
compound, hydriodic acid, HI, which is the active ingredient in an 
official syrup of that name. The acid can be obtained by bringing 
iodine in contact with hydrogen sulphide, but is preferably made by 
decomposition of an alkali iodide by tartaric acid. In the official 
formula for the syrup the following reaction, yielding hydriodic acid, 
takes place: KI + H 2 C 4 H 4 6 = HI + KHC 4 H 4 6 , the resulting 
acid potassium tartrate being removed partly by using a hydro- 
alcoholic solvent and partly by exposing the mixture to cold. 165.56 
parts of potassium iodide yield 127.53 parts of hydriodic acid ; hence 
the 13 Gm. used in the official formula should yield 10 Gm., or suf- 
ficient to make 1000 Gm. of syrup of the required strength, 1 per 
cent, by weight. The potassium hypophosphite ordered in the Phar- 
macopoeia is added to preserve the acid solution, for, if any iodine 
should be liberated, the following reaction would take place : 
KH 2 P0 2 + 2I 2 + 2H 2 = 3HI + KI + H 3 P0 4 , the syrup thus 
being restored to its original conditiou. In all probability there are 
traces of free hypophosphorous acid present in the syrup prepared 



CHLORINE, BROMINE, AND IODINE. 413 

according to the Pharmacopoeia, since 12 Gm. of tartaric acid are 
used, of which only 11.75 + Gm. are required for the potassium 
iodide; for complete decomposition of the hypophosphite, 1.44 Gm. 
of tartaric acid would be necessary. 

The valuation of syrup of hydriodic acid, made by means of y^- sil- 
ver nitrate solution, depends upon the following reaction : HI -f~ 
AgNO s = Agl + HNO s , 127.53 parts of the acid requiring 169.55 
parts of the silver salt for complete precipitation ; hence each Cc. of 
the decinormal solution containing 0.016955 Gm. of AgN0 3 repre- 
sents 0.012753 Gm. of HI. Potassium chromate is used to indicate 
the end of the reaction, by forming red silver chromate as soon as 
the hydriodic acid has all been precipitated as silver iodide ; silver 
chromate, however, is soluble in acid and alkaline liquids, and am- 
monia water is therefore added to the syrup to exact neutrality, so as 
to prevent the liberation of nitric acid which would interfere with the 
precipitation of the silver chromate aud thus vitiate the end reaction. 
This neutralization in no wise interferes with the valuation, the reac- 
tions taking place as follows : 

1. HI + NH 4 OH = NH 4 I + H 2 (). 

2. NHJ + AgN0 3 = Agl + NH 4 N0 3 . 



CHAPTEE XXXVIII. 

SULPHUR, PHOSPHORUS, CARBON, AND BORON. 

Sulphur is found widely diffused, both iu the free state and in 
combination. While by far the greater portion of sulphur used in 
this country conies from Italy, it is now also successfully mined in 
the States of California, Nevada, and Utah, a bed of sulphur 2000 
feet square and over 60 feet thick existing in the latter State. Com- 
mercially, sulphur occurs in four varieties, namely, that known as 
stick or roll sulphur, chiefly used for fumigation and bleaching; aud 
sublimed, washed, and precipitated sulphur, extensively used in medi- 
cine. Roll sulphur, also known as brimstone, is prepared by heat- 
ing the crude sulphur obtained from various sources, allowing im- 
purities to settle and pouring the fused sulphur into cylindrical 
moulds in which it is allowed to congeal. 

Sublimed Sulphur, as its name indicates, is obtained by vaporizing 
sulphur and passing the vapor into large stone or brick chambers, 
the temperature of which is not allowed to rise above 100° or 110° 
C. (212° or 230° F.), where the sulphur is deposited in partly crys- 
talline and partly amorphous particles known as flowers of sulphur. 
The two varieties can be separated from each other by treatment with 
carbon disulphide, which dissolves the amorphous but not the crystal- 
line sulphur. In boiling solutions of alkali hydroxides, sulphur is 
perfectly soluble, forming such compounds as alkali pentasulphide 
and thiosulphate. Nearly all sulphur is contaminated with arsenic 
and this, as arsenic tersulphide, As 2 S 3 , together with traces of sele- 
nium and some sulphuric acid formed by oxidation, are the usual 
impurities found in sublimed sulphur. Not more than one-half 
per cent, of fixed impurities should remain upon ignition. 

Washed Sulphur is recognized in the Pharmacopoeia as Sulphur 
Lotum and is prepared by digesting sublimed sulphur with diluted 
ammonia water. This treatment removes any sulphuric acid and 
arsenic sulphide present as ammonium sulphate, arsenite, and sulph- 
arsenite, according to the following reaction : H 2 S0 4 -f- As 2 S 3 + 
8NH 4 OH=(NH 4 ) 2 S0 4 + (NH 4 ) 3 As0 3 + (NH 4 ) 3 AsS 3 + 5H 2 0. The 
mixture is subsequently strained and the resulting purified sulphur 
is washed with cold water to remove excess of ammonia. In the 
official test for the absence of arsenic, the latter substance would 
unite with ammonia, as above stated, and be precipitated as As 2 S 3 , 
upon addition of hydrochloric acid. Since traces of selenium are 
sometimes present, the Pharmacopoeia gives a special test for the 
same, which depends upon the formation of potassio-selenium cyanide, 



SULPHUR, PHOSPHORUS, CARBON, AND BORON. 415 

KSeCN ; this is decomposed subsequently by hydrochloric acid, sepa- 
rating selenium, which imparts a reddish color to the liquid. Washed 
sulphur should be protected against a damp atmosphere, otherwise 
slow oxidation sets in and an acid reaction becomes perceptible. 

Precipitated Sulphur, also known as lac sulphuris or milk of sul- 
phur, is made from sublimed sulphur by first uniting this to an 
alkali and then decomposing the resulting compound with an acid. 
Milk of lime is preferred mainly on account of its cheapness ; upon 
boiling it with sulphur, both pentasulphide and thiosulphate are 
obtained in solution, thus : 12S -f- 3CaO = 2CaS 5 + CaS 2 3 . The 
Pharmacopoeia directs that hydrochloric acid shall be added to the 
clear filtrate until the latter is nearly neutralized, but still exhibits 
an alkaline reaction ; this is partly to avoid decomposition of the 
calcium thiosulphate, which would yield sulphur insoluble in carbon 
disulphide and in a coarser state of division, and partly to prevent 
the precipitation of any arsenic trisulphide, for, if arsenic had been 
present in the sublimed sulphur, it would have formed calcium 
sulpharsenate, Ca 3 As 2 S 8 , which is soluble in the alkaline liquid, but 
is decomposed by acids. The official process causes a decreased yield 
of precipitated sulphur, but a purer product, the final reaction being 
only between the calcium pentasulphide and hydrochloric acid. 
Sulphuric acid is sometimes used in place of hydrochloric acid, but is 
not permissible, since it would contaminate the sulphur with insoluble 
calcium sulphate, whereas hydrochloric acid yields calcium chloride, 
easily removable by washing. 

Sulphur forms two compounds with iodine, a monoiodide, S 2 T 2 , and 
a hexiodide, SI 6 ; only the former is of interest to pharmacists, as it 
is sometimes used by physicians in the form of an ointment. The 
official directions for making sulphur iodide are very simple, and, 
as union of the two elements takes place at a moderately elevated 
temperature, loss of iodine can be easily avoided. The compound 
must be preserved in well-stoppered vials, as it readily decomposes 
when exposed to the air ; the union is not a very strong one, as 
boiling water is capable of abstracting all the iodine from it. 

Phosphoeus occurs in nature chiefly as calcium phosphate which 
makes up the structure of bone and is found as extensive mineral 
deposits. Pure phosphorus is obtained by distilling calcium meta- 
phosphate with sand and charcoal. Owing to its great avidity for 
oxygen and ready inflammability, it must be preserved under water 
and care is necessary in handling it. Elementary phosphorus is 
used to a considerable extent in medicine, entering into the compo- 
sition of four official preparations, the elixir, oil, pill, and spirit of 
phosphorus; all but the second named have already been considered 
in previous chapters, on pages 234, 240, and 332, where also special 
precautions regarding the weighing of small quantities of phosphorus 
have been given. 

Phosphorated Oil, or Oleum Phosphoratum of the Pharmacopoeia, 
contains 1 per cent, of phosphorus, about 90 per cent, of expressed oil 



416 PHARMACEUTICAL CHEMISTRY. 

of almond, and about 10 per cent, of ether, all by weight. When the 
oil is heated to 250° C. (482° F.) for fifteen minutes, air and mois- 
ture are first expelled and afterward certain organic matters are 
volatilized, the oil becoming colorless ; upon cooling, flocculi are de- 
posited, which are removed by filtration. The addition of ether 
materially aids in the preservation of the solution. Each gramme of 
phosphorated oil represents 10 milligrammes of phosphorus, which 
is equal to about J grain in every fluidrachm. 

Carbon is recognized, iu the Pharmacopoeia, in the form of wood 
charcoal and animal charcoal ; the former will be considered in con- 
nection with the products of woody fibre (see Cellulose). Animal 
charcoal is extensively employed as a decolorizing agent by manu- 
facturing chemists; it is prepared by roasting bone in iron cylinders 
until vapors cease to be given off; the residuary charcoal mixed with 
large proportions of inorganic constituents is known in its crude 
state as bone-black. Meat and blood are also made to yield animal 
charcoal by a somewhat similar process. Purified animal charcoal 
differs from crude bone-black in having been repeatedly treated with 
boiling diluted hydrochloric acid, whereby all acid soluble impurities, 
such as calcium carbonate and phosphate, are removed. By this 
treatment, animal charcoal loses about 80 per cent, in weight, leav- 
ing a small proportion (4 per cent.) of siliceous matter mixed with 
the purified charcoal. If not completely carbonized, animal charcoal 
will impart color to water if boiled with the same in the presence of 
potassium hydroxide. The remarkable decolorizing property of 
animal charcoal is due to the very fine state of division of the carbon 
and its consequent increased surface attraction. While crude animal 
charcoal is largely used for neutral solutions in the arts, only the 
purified article can be employed for acid liquids or delicate chemical 
solutions. So-called spent charcoal, charged with organic matter, 
can be regenerated by appropriate heating. 

The only preparation of carbon to be considered is carbon disul- 
phide, CS 2 , which is not employed medicinally, but is a valuable 
solvent for caoutchouc, fats, and many other substances. It is pre- 
pared by direct union of charcoal and sulphur, vapors of the latter 
being passed over the former, heated to redness, and then condensed 
in suitable receivers. It is freed from dissolved sulphur by distilla- 
tion on a water-bath, while hydrogen sulphide, which is also formed, 
is removed by agitation with mercury ; the liquid is further rectified 
by distillation with wax or fat, whereby certain offensive sul- 
phur compounds are removed. When exposed to light, carbon 
disulphide assumes a yellow color and develops a fetid odor, owing 
to decomposition. The Pharmacopoeia demands the absence of dis- 
solved sulphur, hydrogen sulphide, and sulphur dioxide. 

Boron is never used in pharmacy or medicine in its free state. 
Its compound with oxygen, boric acid, will be considered in the next 
chapter. 



CHAPTER XXXIX 

THE INORGANIC ACIDS. 



The different combinations of hydrogen, as well as of hydrogen 
and oxygen, with other uon-metallic elements, yield a class of com- 
pounds known as inorganic acids, which, being extensively employed, 
are of great importance to the pharmacist. The presence of hydro- 
gen, whether it has been introduced in its elementary state or in the 
form of water, lends to these compounds their peculiar acid char- 
acter. Compounds with oxygen only, possess no acid properties and 
are termed anhydrides or simply oxides ; they, however, will unite 
chemically with water to form well-defined acids ; thus we have sul- 
phurous and sulphuric anhydrides, S0 2 aud SO s , known also as sul- 
phur dioxide and trioxide, which, combining with water, yield 
sulphurous and sulphuric acids, as S0 2 -f- H 2 = H 2 S0 3 and S0 3 -|- 
H 2 = H 2 S0 4 ; carbon dioxide, C0 2 , in contact with water, yields 
carbonic acid, H 2 C0 3 ; nitric anhydride, or nitrogen pentoxide, N 2 5 , 
yields nitric acid, HIS T 3 , thus N 2 5 + H 2 = 2HNO s ; phosphoric 
anhydride or phosphorus pentoxide, P 2 5 , will yield with water 
phosphoric acid, H 3 P0 4 , thus P 2 5 + 3H 2 = 2H 3 P0 4 , etc. 

Acids, as is well known, are characterized by a sour taste, the 
property of changing the color of blue litmus paper to red, of neu- 
tralizing alkalies, and of forming with these and other bases well- 
defined salts. The salts thus formed are not always neutral com- 
pounds, which fact is due to different basicity of the various acids, 
depending upon the number of replaceable hydrogen atoms present 
in the acid ; hence the terms mono-, di-, tri-, and tetrabasic, referring 
to the presence of 1, 2, 3, or 4 atoms of hydrogen, which can be re- 
placed by as many basylous atoms or groups, giving rise to normal 
and acid salts. Normal salts are such as are formed by complete 
saturation of an acid by a base, or, in other words, they are produced 
whenever all the replaceable hydrogen of an acid is replaced by a 
base ; acid salts, on the other hand, still retain a part of the replace- 
able hydrogen of acids, and are the result of imperfect neutralization 
of an acid by a base. (Examples, KN0 3 and Na 2 SG 4 are normal 
salts, while N aHCO s and KH 2 P0 4 are acid salts.) Monobasic acids 
can never form acid salts. In the pharmacopceial chemical formulas 
for acids the replaceable hydrogen is stated first, hence the basicity 
of the acid can be seen at a glance; thus hydrochloric, hydrobromic, 
hypophosphorous, and nitric acids are all mouobasic, sulphurous and 
sulphuric acids are dibasic, while boric and phosphoric acids are 
tribasic. 

27 



418 PHARMACEUTICAL CHEMISTRY. 

Both crude and purified acids are offered for sale by manufac- 
turers ; the former, while suitable for many technical purposes, 
should never be used for pharmaceutical preparations. A very im- 
portant point in connection with inorganic acids is the percentage of 
absolute acid present in the commercial solutions sold under their 
respective names. The Pharmacopoeia, in every instance, designates 
the percentage strength of the official acids, and pharmacists should 
insist on being furnished such acids by manufacturing chemists ; the 
designation C. P. (chemically pure), placed on the labels of acid 
bottles, is no clue as to the strength of the solution ; either the initials 
U. S. P. or the percentage of absolute acid should be stated. Manu- 
facturing chemists will not be slow in recognizing the justice of such 
a demand, if pharmacists insist upon it; otherwise, the same uncer- 
tainty as to strength will continue. All working formulas of the 
Pharmacopoeia, requiring the use of inorganic acids, are based upon 
the assumption that acids of official strength will be used. Absolute 
purity is not demanded for official acids, for, while this is essential 
for chemical reagents, it is considered unnecessary for medicinal acids, 
and, if insisted upon, would greatly enhance the cost of the article 
without improving the acid for medicinal or pharmaceutical pur- 
poses. Certain impurities, which it would be difficult to remove 
entirely, except at considerable expense, are allowed by the Pharma- 
copoeia to be present within prescribed limits. As different acids 
have different saturating powers, the official volumetric determinations 
are only useful in fixing the strength of the acid examined, after the 
absence of other acids has been proved by the tests prescribed for 
that purpose. 

Only such inorganic acids will be considered here as are designated 
in the Pharmacopoeia, and are therefore of special interest to the 
student of pharmacy. Details of the manufacture of the leading acids 
will not be essayed, as the text-books on chemistry furnish all such in- 
formation. While there must naturally exist a great diversity in the 
strength of the various so-called strong acids, the Pharmacopoeia has 
fixed the proportion of absolute acid in all official diluted inorganic 
acids at 10 percent., with the exception of diluted nitro-hydrochloric 
acid. With one exception, boric acid, all the official inorganic acids 
are liquid, although the Pharmacopoeia also designates as acids two 
compounds, arsenic tri oxide and chromium trioxide, which will be 
considered elsewhere. 

The following is a list of the official inorganic acids : Boric Acid, 
Diluted Hydrobromic Acid, Hydrochloric Acid, Diluted Hydrochloric 
Acid, Diluted Hypophosphorous Acid, Nitric Acid, Diluted Nitric 
Acid, Nitrohydrochloric Acid, Diluted Nitrohydrochloric Acid, Phos- 
phoric Acid, Diluted Phosphoric Acid, Sulphuric Acid, Aromatic 
Sulphuric Acid, Diluted Sulphuric Acid, Sulphurous Acid. 

Boric Acid. H 3 B0 3 or B(OH) 3 . Boric acid occurs in nature 
both in a free and combined state, the free acid, in the form of 



THE INORGANIC ACIDS. 41 9 

vapor, issuing with steam from the earth in volcanic regions, par- 
ticularly in Tuscany, Italy, while the combined acid is usually found 
as sodium tetraborate or borax. Medicinal boric acid is probably all 
obtained by decomposition of a boiling solution of borax with hydro- 
chloric acid, which latter is preferable to sulphuric acid, as it can be 
more readily removed by washing from the crystals of boric acid ; 
the reaction is a very simple one — (Xa 9 B 4 7 + 10H 9 O) + 2HC1 = 
4H 3 B0 3 + 2NaCl + 5H 2 0. When heated, boric acid gradually loses 
water and is converted into metaboric acid, HB0 2 , with increasing 
temperature, into tetraboric, H 2 B 4 O r , and, finally, above 160° C. 
(320° F.) all hydrogen is eliminated in the form of water and boron 
trioxide remains ; thus 2H 3 B0 3 = B 2 3 + 3H 2 0. 

The Pharmacopoeia requires the absence of all impurities in boric 
acid except traces of iron. Its chief characteristics are that it imparts 
a green color to the flame of burning alcohol, and that it changes 
the yellow color of turmeric paper brown even in the presence of 
hydrochloric acid. 

Diluted Hydrobromic Acid. An aqueous solution containing 
10 per cent, by weight of absolute HBr. Pure hydrobromic acid is a 
gaseous compound, and is rather unstable. The medicinal acid is 
prepared, by manufacturers, usually of two strengths, 34 per cent, 
and 10 per cent., the former being the more economical article to 
purchase, as the requisite proportion of water to reduce it to the 
official acid can be easily added by the pharmacist, 10 Gm. of 34 
per cent, acid mixed with 24 Gm. of distilled water yielding 34 Gm. 
of 10 per cent. acid. Hydrobromic acid can be obtained in several 
ways, but is usually made, on a large scale, by a method first sug- 
gested by Dr. Squibb. Moderately diluted sulphuric acid is poured 
slowly, and with constant stirring, into a hot saturated solution of 
potassium bromide, when the following decomposition takes place: 
2KBr + H 2 S0 4 = 2HBr + K 2 S0 4 ; after twenty-four hours the 
potassium sulphate has crystallized out, the solution of hydrobromic 
acid is poured off, and the crystals are slowly washed with ice-cold 
water to recover any adhering acid. Finally, the acid liquid is dis- 
tilled in a glass retort, on a sand-bath, nearly to dryness. Its 
strength is ascertained by titration with normal potassium hydroxide 
solution, and sufficient water added to produce either a 34 or 10 per 
cent, solution as desired. 

For prepariug small quantities of the official acid, the precipita- 
tion method of Wade and Fothergill may be employed, which is 
based on the decomposition of potassium bromide with tartaric acid ; 
thus KBr + H 2 C 4 H 4 6 = HBr -f- KH0 4 H 4 O 6 . 1 1.9 Gm. of potas- 
sium bromide and 15 Gm. of tartaric acid are each dissolved in 30 
Cc. of cold distilled water ; the acid solution is poured into the saline 
solution, and the mixture, after having been well shaken for five or 
ten minutes, is placed in ice-water or an ice-chest for twenty- four or 
thirty-six hours; it is then filtered, and the vessel and filter carefully 



420 PHARMACEUTICAL CHEMISTRY. 

washed with ice-cold water until the filtered liquid weighs 81 Gm. 
A small quantity of acid potassium tartrate is apt to remain in the 
diluted acid prepared by this method. 

The Pharmacopoeia excludes all impurities except slight traces of 
arsenic, and directs that 8.08 Gm. of the official diluted acid shall 
require 10 Cc. of * KOH solution for neutralization. According 
to the equation, KOH + HBr = KBr + H 2 0, each Cc. of ? KOH 
solution containing 0.05599 Gm. of KOH corresponds to 0.08076 
Gm. HBr, and 10 Cc. would correspond to 0.8076 Gm., which is 
practically 10 per cent, of 8.08 Gm. The official acid has a specific 
gravity of about 1.077 at 15° C. (59° F.). 

Hydrochloric Acid. This acid may be prepared quite pure by 
decomposing sodium chloride with pure sulphuric acid and con- 
ducting the gas into water. The crude acid of commerce is often 
obtained, as a by-product, in the manufacture of sodium or potas- 
sium carbonates from the respective chlorides ; since sulphates are 
first made in this process by acting on the chlorides with sulphuric 
acid, the reactions are the same in the manufacture of crude and 
pure acid, and possibly occur in two distinct steps, namely : 1. 
NaCl + H 2 S0 4 = HC1 + NaHS0 4 . 2. NaCl + NaHS0 4 = HC1 + 
RTa 2 S0 4 . The crude acid of commerce is often of a deep yellow 
color, owing to organic matter and traces of iron in solution ; it 
should not be employed for pharmaceutical preparations. 

Official hydrochloric acid should be free from all impurities, 
except a bare trace of non-volatile substances and arsenic, the latter 
derived in all probability from the sulphuric acid. It has a specific 
gravity of about 1.163 at 15° C. (59° F.), and should contain 31.89 
per cent, by weight of absolute HC1, which is determined by 
titration with * KOH solution. The Pharmacopoeia directs the use 
of 3.64 Gm. for the assay, which, at 31.89 per cent., should contain 
1.1608 Gm. of HC1. Since each Cc. of » KOH solution cor- 
responds to 0.0364 Gm. of HC1, the 3.64 Gm. of acid will require 
31.9 Cc. of 5 KOH solution for complete neutralization, for 1.1608 
divided by 0.0364 yields 31.89+. 

Strong hydrochloric acid, when exposed to the air, usually pro- 
duces white fumes, due partly to the moisture in the air and partly 
to the ammonia more or less present, ammonium chloride being 
formed. 

Diluted Hydrochloric Acid is made from the official acid by 
mixing it with distilled water, in the proportion of 10 parts of the 
former to 21.9 parts of the latter, by weight, or, as the Pharmacopoeia 
gives it, 100 Gm. of the acid with 219 Gm. of distilled water. This 
must yield a liquid containing 10 per cent, of absolute HC1, for the 100 
Gm. of official hydrochloric acid contain 31.89 per cent, of HC1, and 
31.89 Gm. is equal to 10 per cent, of 319 Gm. Diluted hydro- 
chloric acid has a specific gravity of about 1.050 at 15° C. (59° F.), 



THE INORGANIC ACIDS. 421 

and corresponds in all its properties, reactions, and tests to the 
official stronger acid, except that it is odorless and produces no fumes 
when exposed to the air, and that 3.64 Gm. require only 10 Cc. 
of ~ KOH solution for neutralization. 

Diluted Hypophosphorous Acid. Hypophosphorous acid is a 
strong reducing agent used in pharmacy chiefly to prevent oxidation 
of certain unstable solutions, such as those of hydriodic acid. It 
can be obtained by decomposition of any of the soluble hypophos- 
phites with an acid yielding an insoluble compound. The National 
Formulary directs the use of potassium hypophosphite and tartaric 
acid, when the following reaction occurs : KH 2 P0 2 + H 2 C 4 H 4 6 = 
HH 2 P0 2 + KHC 4 H 4 6 , the newly formed acid potassium tartrate 
being removed both by the use of a hydro-alcoholic solvent and 
cold. Calcium hypophosphite and oxalic acid have also been 
employed with excellent results, 69 parts of the former requiring 
50.4 parts of the latter, and the reaction occurring thus : Ca (H 2 P0 2 ) 2 
+ H 2 C 2 4 = 2HH 2 P0 2 + CaC 2 4 . The official acid contains 10 
per cent, of absolute HH 2 P0 2 , and has a specific gravity of about 
1.046 at 15° C. (59° F.), but, for manufacturing purposes, a 50 per 
cent, acid is also on the market. Traces of phosphoric, oxalic, and 
tartaric acids, as also of potassium, are permitted, as indicated in the 
official tests. The strength of the acid may be determined by both 
its neutralizing and its reducing powers, the latter being the more 
reliable, however, although the two tests may be used to corroborate 
each other. The reaction between hypophosphorous acid and potas- 
sium permanganate takes place according to the following equation : 
5HH 2 P0 2 + 6H 2 S0 4 + 4KMn0 4 = 5H 3 P0 4 +2K 2 S0 4 + 4MnS0 4 + 
6H 2 ; hence each Cc. of ^ KMn0 4 solution corresponds to 
0.001647 Gm. of absolute HH 2 P0 2 . In the pharmacopoeial test, 
0.5 Gm. of diluted hypophosphorous acid is used, which, as seen 
above, would require 30.3 Cc. of ^ KMn0 4 solution for complete 
oxidation, known by the appearance of a permanent pink tint ; it 
has been found more convenient, however, to add at once an excess 
of the KMn0 4 solution, and determine the actual excess by re- 
titration with oxalic acid, which involves a further reaction, thus : 
5(H 2 C 2 4 + 2H 2 0) + 3H 2 S0 4 + 2KMn0 4 = 10CO 2 + K 2 S0 4 + 
2MnS0 4 -f 18H 2 0. As each Cc. of deciuormal oxalic acid solution 
corresponds in value exactly to 1 Cc. of decinormal potassium per- 
manganate solution, simple subtraction of the number of Cc. neces- 
sary to discharge the purple color will indicate the actual number of 
Cc. of ^ IvMn0 4 solution reduced by the sample of hypophosphorous 
acid used, and this multiplied by 0.001647 gives the total amount 
of HH 2 P0 2 present ; from these figures the percentage can be readily 
calculated. 

Xitric Acid. When potassium or sodium nitrate is treated with 
sulphuric acid, nitric acid is liberated, and may be condensed in 



422 PHARMACEUTICAL CHEMISTRY. 

suitable receivers. The reaction, in the case of potassium nitrate, 
occurs as follows : KN0 3 -f- H 2 S0 4 = HNO s + KHS0 4 ; in the case 
of Chili saltpetre, provided a sufficient quantity of sodium nitrate be 
used, two distinct reactions mav be said to occur, namely : 1. NaN0 3 
+ H 2 S0 4 = HN0 3 + NaHS0 4 ; 2. NaHS0 4 + NaN0 3 =HN0 3 + 
Na 2 S0 4 . Sodium nitrate affords a larger yield than potassium 
nitrate, since the acid sodium sulphate reacts with the undecomposed 
nitrate at a much lower temperature than the acid potassium sul- 
phate, the latter requiring a temperature at which the nitric acid is 
apt to be decomposed. 

The Pharmacopoeia demands absolute purity for nitric acid. If 
exposed to sunlight, the acid soon undergoes decomposition, a red 
color being imparted to the liquid, due to the formation of nitrogen 
tetroxide, N 2 4 , hence the acid must be kept in a dark place. Nitric 
acid of different strengths is placed upon the market by manufacturing 
chemists, ranging from 1.21 to 1.50 specific gravity, hence care is ne- 
cessary to obtain the only kind recognized by the Pharmacopoeia, which 
contains 68 per cent, of absolute HN0 3 and has a specific gravity of 
1.414 at 15° C. (59° F.), otherwise considerable annoyance may be 
experienced when nitric acid is to be used as an oxidizing agent in 
any of the official preparations. 

Nitric acid, being the most corrosive of the official acids, requires care 
in handling ; in contact with the skin, it acts chemically on the same 
and produces a deep yellow stain, this behavior, characteristic of 
nitric acid with albuminoid substances, beiug known as the xantho- 
proteic reaction. 

Each Cc.of I KOH solution will represent 0.06289 Gm. of abso- 
lute HN0 3 , nitric acid being monobasic, and 34 Cc. will, therefore, 
be necessary to neutralize 3.145 Gm. of the official acid, for 68 per 
cent, of 3.145 is 2.1386, and 2.1386 divided by 06289 yields 34. 

The so called nitrous acid of commerce is simply nitroso-nitric 
acid, that is, nitric acid containing variable amounts of nitrogen 
tetroxide. 

Diluted Nitric Acid is made by diluting official nitric acid 
with distilled water in the proportion of 100 Gm. of the former to 
580 Gm. of the latter, and must, therefore, contain 10 per cent, of 
absolute HN0 3 , 100 Gm. of official acid containing 68 Gm., which 
are equal to 10 per cent, of 680 Gm., the total weight of the finished 
product. It has a specific gravity of about 1.057 at 15° C. (59° F.), 
and 6.29 Gm. should require 10 Cc. of y KOH solution for com- 
plete neutralization. 

Nitrohydrochloric Acid. This preparation, which is also 
known as nitromuriatic acid, is not of a definite chemical composi- 
tion, but is considered by physicians a valuable remedial agent. 
When strong nitric and hydrochloric acids are brought into contact, 
mutual decomposition takes place, the composition of the finished 



THE IXORGAXIC ACIDS. 423 

product depending upon the proportions of the acids used aud the 
temperature at which they have been mixed. The Pharmacopoeia 
directs 18 volumes of nitric acid and 82 volumes of hydrochloric 
acid, and, when so mixed, the following reactions probably take 
place : HNO s + 3HC1 = XOC1 + Cl 2 + 2H 2 and 2HX0 3 + 
6HC: = 2N0C1 2 + Cl 2 + 4H 2 0, nitrosyl mono- and dichloride and 
water being formed, while chlorine is liberated. The mixture is at 
first colorless, but, as react iou progresses, an orange-red color is de- 
veloped and effervescence is observed ; the liberated gas is very 
irritating, hence the operation should be conducted in a cool place, 
in the open air or under a flue. This preparation should never be 
made extemporaneously, as severe accidents may result from such a 
proceeding ; sufficient time must be allowed for complete reaction, 
which is known by cessation of effervescence, after which the liquid, 
which has assumed a green-yellow color, should be preserved in dark, 
glass-stoppered bottles, in a cool place. Nitrohydrochloric acid must 
never be dispensed in completely filled bottles, and the patient 
should be cautioned against keeping it in a warm room. The acid 
is also known as chloro-nitrous acid and aqua regia, and owes its 
power of dissolving gold to the free chlorine and feeble chlorine 
compounds present. 

Diluted Nitrohydrochloric Acid is of nearly one-fourth the 
strength of the stronger acid, 22.5 per cent., and is prepared in 
exactly the same manner, the diluent, distilled water, not being added 
until all effervescence has ceased. The British Pharmacopoeia pre- 
pares this acid by mixing the stronger acids at once with the water 
and setting the mixture aside for fourteen days. Conflicting views 
exist regarding the composition of the finished product, some author- 
ities contending that, when made bv diluting the strong acids at 
once with water, the same reactions will occur as in a mixture of the 
acids alone, except that the decomposition is more gradual, while 
others assert that little or no change will take place, and that, in 
fact, the decomposed strong acids will be again restored to their 
original condition upon the addition of water, nitric aud hydro- 
chloric acids being regenerated. Certain it is that the diluted nitro- 
hydrochloric acid diifers from the strong acid in being free from 
color and possessing only a faint odor of chlorine when freshly made, 
which is gradually lost. The author has never observed any effer- 
vescence or change of color or odor upon mixing the strong acids 
direct with water and allowing the mixture to stand. 

Phosphoric Acid. The official acid is a dense syrupy liquid 
containing 85 per cent, of absolute orthophosphoric acid, H 3 P0 4 or 
PO(OH) 3 , and has a specific gravity of 1.710 at 15° C. (59° F.). 
Medicinal phosphoric acid should all be made direct from phos- 
phorus; usually oxidation by means of nitric acid is resorted to, each 
part of phosphorus requiring about 3J- parts of absolute nitric acid 



424 PHARMACEUTICAL CHEMISTRY. 

for complete conversion, according to the following equation: 
5HN0 3 + P s + 2H 2 = 3H 3 P0 4 -f 5NO. 

In order to control the reaction, about an equal weight of water is 
mixed with a portion of the nitric acid contained in a flask, the phos- 
phorus is added, and the whole heated on a water-bath ; when the 
reaction slackens, the balance of the nitric acid is added, undiluted, 
small portions at a time, and the heat is continued until all the phos- 
phorus is dissolved, after which the liquid is heated in a porcelain 
dish, on a sand-bath, at a temperature not exceeding 190° C. (374° 
F.), until all traces of nitric acid have been removed. The object of 
limiting the temperature is to avoid conversion of the orthophospho- 
ric acid into pyrophosphoric acid, which occurs at 200° C. (392° F.) 
and over. Phosphorus is frequently contaminated with arsenic, which 
is best removed, at this stage of the process, by diluting the acid 
liquid with water, passing a stream of hydrogen sulphide through it 
for several hours and afterward setting the liquid aside for twenty- 
four hours to allow the arsenic sulphide to subside. After filtration, 
the excess of gas is removed by heating and the liquid evaporated to 
the desired density, every 100 Gm. of phosphorus used yielding about 
370 Gm. of official phosphoric acid. This is essentially the modified 
process suggested some years ago by Dr. Squibb. 

In 1875, Markoe proposed the following process, which has since 
then been used, with marked success, on a large scale. 900 Gm. of 
phosphorus are placed in a stone jar and covered with 5400 Gm. of 
water, after which 10 Gm. of iodine are added and the mixture 
stirred so as to bring the iodine into contact with the phosphorus. 
From a glass- stoppered burette or funnel, 60 Gm. of bromine are now 
added, drop by drop, in such a manner that the bromine shall strike 
the phosphorus as it falls below the water. Phosphorus pentaiodide 
and pentabromide, PI 5 and PBr 5 , chiefly the latter, are formed by 
direct union, and, when the reaction has ceased, 5400 Gm. of nitric 
acid are added, the jar is placed in cold water or surrounded with 
ice, to control the rate of oxidation, and set aside until solution of 
the phosphorus has been effected. The acid liquid is then evaporated 
and treated as above. The phosphorus iodide and bromide are de- 
composed by the water present, forming phosphoric, hydriodic, and 
hydrobromic acids ; the last two are decomposed by the nitric acid 
regenerating iodine and bromine with the liberation of nitric oxide. 
These reactions, continuing until all the phosphorus has been con- 
verted into phosphoric acid, may be expressed by the following 
equations : 1 . PI 5 + 5PBr 5 + 24H 2 = 6H 3 P0 4 + 5HI + 25HBr ; 
2. HI + 5HBr + 2H]ST0 3 = I + 5Br + 2NO + 4H 2 0. The pro- 
cess can be conducted with bromine alone, but the presence of iodine has 
been found to modify the action between the phosphorus and bromine. 

The impurities likely to be met with in phosphoric acid can, as a 
rule, be avoided in the process of manufacture, phosphorous acid 
being due to insufficient oxidation, while meta- and pyrophosphoric 
acids arise from the use of excessive heat. 



THE INORGANIC A CID& 425 

Phosphoric acid made from phosphorus should be miscible with 
tincture of ferric chloride iu all proportions, but, if made from glacial 
phosphoric acid, it causes turbidity, which is in part due to the pres- 
ence of sodium metaphosphate in the glacial acid. 

The value of the volumetric assay of phosphoric acid depends 
largely upon the indicator employed ; complete neutralization is not 
feasible, since the normal alkali phosphate itself gives an alkaline 
reaction. Phosphoric acid is tribasic, and, therefore, capable of form- 
ing three different compounds with the alkalies, namely, KH 2 P0 4 , 
K 2 HP0 4 , and K 3 P0 4 ; the last-named salt is alkaline to all color- 
indicators, whereas the other two are either acid, alkaline, or neutral 
to different indicators. With phenolphtalein, KH 2 P0 4 shows an 
acid reaction, but K 2 HP0 4 a neutral reaction, but with methyl- 
orange and Congo-red, KH 2 P0 4 already shows a neutral reaction, 
and K 2 HP0 4 an alkaline reaction. Therefore, when phenolphtalein 
is used as an indicator, as prescribed in the Pharmacopoeia, two 
molecules of potassium hydroxide will be required for every molecule 
of absolute phosphoric acid to form the salt K 2 HP0 4 , secondary or 
dibasic potassium phosphate, according to the equation H 3 P0 4 -f 
2KOH = K 9 HP0 4 + 2H 2 0. Each Cc. of f KOH solution, con- 
taining 0.05599 Gm. KOH, will indicate 0.0489 Gm. H 3 P0 4 , when 
the neutral reaction w T ith phenolphtalein is just passed, which is 
shown by a permanent pink tint imparted by a drop of the alkali 
solution. In the official test, at least 17 Cc. of y KOH should be 
required before an alkaline reaction is shown, for 17 X 0.0489 is 
equal to 0.8313, and 85 per cent, of 0.978 is 0.8313. With methyl- 
orange as an indicator, each Cc. of T KOH solution represents 0.0978 
Gm. H 3 P0 4 , for an alkaline reaction (a golden-yellow color) will be 
observed upon the addition of one or two drops in excess of the 
quantity necessary to form primary or monobasic potassium phos- 
phate, KH 2 P0 4 , an equal number of molecules of the acid and alkali 
being concerned in the reaction ; thus, H 3 P0 4 -j- KOH = KH 9 P0 4 -f 
H 2 0. 

Diluted Phosphoric Acid is made from the preceding acid by 
dilution with distilled water in the proportion of one part by weight 
of the strong acid and seven aud one-half parts of water, or 100 Gm. 
and 750 Gm. It contains 10 per cent, of absolute H 3 P0 4 , and has 
a specific gravity of about 1.057 at 15° C. (59° F.). 

Sulphuric Acid. The manufacture of this acid is carried on 
extensively in this country and in Europe, in specially constructed 
factories so arranged that the fumes from burning sulphur or iron 
pyrites are brought into contact w r ith steam and nitric acid vapor iu 
leaden chambers. Nitrogen trioxide is generated and combines with 
more sulphur dioxide, aqueous vapor, aud atmospheric oxygen, 
forming nitrosylsulphuric acid, which, coming into contact with 
water, is decomposed, yielding sulphuric acid and nitrogen trioxide, 



426 PHARMACEUTICAL CHEMISTRY. 

and this, in turn, again unites with more sulphur dioxide, etc. The 
following equations will explain the various steps in the process : 

1. 2S0 2 + 2HN0 3 + H 2 = 2H 2 S0 4 + N 2 3 . 

2. N 2 3 + 2S0 2 + 2 + H 2 = 2SO 2 0HNO 2 . 

3. 2SO 2 0HNO 2 + H 2 = 2H 2 S0 4 + N 2 3 . 

The foregoing are the chief reactions involved in the manufacture 
of sulphuric acid, which condenses and is dissolved in the water cov- 
ering the floor of the leaden chambers, thus forming a dilute acid 
which gradually becomes more concentrated ; it is afterward with- 
drawn, still further concentrated in leaden pans, and finally distilled 
in glass or, preferably, gold-lined platinum retorts. 

Crude sulphuric acid is often colored, and contains nitric and sul- 
phurous acids and lead, the latter beiug readily detected by simple 
dilution with water. Arsenic is almost invariably present, and thus 
is transferred to other substances in the manufacture of which sul- 
phuric acid is used, as hydrochloric and nitric acids, phosphorus, etc. 

When sulphuric acid is mixed with water or alcohol, heat is 
developed and the volume of the mixture is invariably contracted. 
Official sulphuric acid is of oily consistence, and has a specific gravity 
of 1.835 at 15° C. (59° F.). It should be free from lead and other 
mineral impurities, but slight traces of arsenic, nitric, nitrous, and 
sulphurous acids are permitted. The Pharmacopoeia requires the 
presence of not less than 92.5 per cent, of absolute H 2 S0 4 , and, as 
sulphuric acid is bibasic, the following reaction takes place when 
potassium hydroxide is added to complete neutrality: H 2 S0 4 + 
2KOH = E 2 S0 4 + 2H 2 0. Each Cc. of f KOH solution, contain- 
ing 0.05599 Gm. KOH, is equivalent to 0.04891 Gm. H 2 S0 4 . 

Aromatic Sulphuric Acid. An alcoholic solution of sulphuric 
acid, flavored with ginger and cinnamon, containing about 10 per 
cent, by volume, or nearly 20 per cent, by weight, of official acid. It 
is a light-colored liquid having a specific gravity of about 0.939 at 
15° C. (59° F.). The acid should be added to the alcohol slowly in 
a thin stream, with constant stirring, and, when the mixture has 
cooled, the tincture of ginger and oil of cinnamon may be added. 
Upon standing, chemical action ensues and a part of the sulphuric 
acid is gradually converted into ethyl-sulphuric or sulphovinic acid, 
according to the equation H 2 S0 4 + C 2 H 5 OH = C 2 H 5 HS0 4 + H 2 0. 
The new compound, also known as acid ethyl sulphate, is soluble in 
water and alcohol, but cannot be precipitated by barium chloride ; 
by boiling, it is split up into sulphuric acid and alcohol ; hence the 
Pharmacopoeia directs, in the official volumetric test for aromatic 
sulphuric acid, that the dilute mixture shall be boiled for a few min- 
utes and cooled before titrating it. 

The aromatic sulphuric acid of the present Pharmacopoeia differs 
considerably from the preparation of the same name of the 1870 



THE INORGANIC ACIDS. 427 

Pharmacopoeia, formerly often prescribed under the name of Elixir 
of Vitriol. The latter preparation was of a brownish-red color, and 
very prone to precipitation ; it was made by percolating 1 troy ounce 
of ginger and If troy ounces of cinnamon with 1 pint of alcohol, 
and adding the resulting tincture to a previously prepared and 
cooled mixture of 1 pint of alcohol and 6 troy ounces of sulphuric 
acid. 

Dilute Sulphuric Acid is made by diluting 10 parts by weight 
of official sulphuric acid with 82J parts of distilled water, or 100 Gm. 
of the former with 825 Gm. of the latter. The acid should be added 
gradually, with constant stirring, on account of the heat developed. 
It contains 10 per cent, of absolute H 2 S0 4 and has a specific gravity 
of about 1.070 at 15° C. (59° F.). 

Sulphurous Acid. Under this name the Pharmacopoeia recog- 
nizes an aqueous solution of sulphur dioxide, containing not less than 
6.4 per cent, by weight of the gas. The official directions for pre- 
paring the solution are explicit, and, if followed, cannot fail to yield 
a satisfactory product. The charcoal acts as a deoxidizing agent 
upon the sulphuric acid, sulphur dioxide and carbon dioxide being 
generated, as shown in the following equation : 4H 2 S0 4 -f- C 2 = 
4S0 2 + 2C0 2 + 4H 2 0. Heat is necessary to induce the reaction, 
and in order to intercept any impurities which may be mechanically 
carried over with the escaping gases the latter are made to pass 
through water contained in a wash-bottle. The carbon dioxide will 
escape from the bottle containing the distilled water as the sulphur 
dioxide is absorbed, since it is insoluble in a solution of sulphurous 
acid ; it may be retained, however, in the solution of sodium car- 
bonate unless much S0 2 gas should also pass over. The use of the 
bottle containing sodium carbonate solution can be readily dispensed 
with if the operation be conducted in the open air or under a flue. 

In the place of charcoal, pure copper foil or turnings may be used 
for the generation of sulphur dioxide ; the yield of gas from an equal 
weight of sulphuric acid, however, will be only one-half of that ob- 
tained with charcoal, as may be seen from the equation 4H 2 S0 4 + 
Cu 2 = 2S0 2 -f 2CuS0 4 -f 4H 2 0, although the evolution of carbon 
dioxide is avoided ; the official process is therefore more economical. 

As in the case of chlorine water, the water intended for the absorp- 
tion of the sulphur dioxide should be kept cold, so as to avoid the 
loss of gas, and the finished solution must be preserved in small, 
completely filled, glass-stoppered vials in a cool, dark place, as the 
sulphurous acid rapidly absorbs oxygen and is converted into sul- 
phuric acid when carelessly exposed, thus losing all its valuable 
medicinal properties. The precautions regarding fracture of the gen- 
erating flask, already stated under chlorine water, should also be 
observed in the case of this solution. 

The pharmacopoeial test with lead acetate paper depends upon the 



428 PHARMACEUTICAL CHEMISTRY. 

reaction between sulphur dioxide and nascent hydrogen (generated 
from zinc with hydrochloric acid), resulting in the formation of 
hydrogen sulphide, thus S0 2 + H 6 = H 2 S + 2H 2 0. Slight traces 
of sulphuric acid are unavoidable, except in freshly made solutions ; 
hence the official limit test. 

The strength of sulphurous acid solutions is determined, volu- 
metrically, with iodine as an oxidizing agent, the following reaction 
taking place : H 2 S0 3 (S0 2 + H 2 0) + I 2 + H 2 = 2HI + H 2 S0 4 , 
2 atoms of iodine converting 1 molecule of sulphurous acid into sul- 
phuric acid. Each Cc. of j-q iodine solution, containing 0.012653 
Gm. iodine, therefore corresponds to 0.003195 Gm. S0 2 , and 2 Gm. 
of the official acid must require at least 40 Cc, for 6.4 per cent, of 2 
is 0.128, and 0.128 divided by 0.003195 yields 40. Starch solution 
is used to indicate the end of the reaction by striking a blue color 
with the least excess of iodine added. 



CHAPTEE XL. 



THE COMPOUNDS OF POTASSIUM. 



The Pharmacopoeia recognizes seventeen salts of potassium, besides 
seven preparations of salts, including three liquids, for which work- 
ing formulas are given ; the following comprise the list : 



Official English Name. 
Potassa, 

Potassa with Lime, 
Sulphurated Potassa, 
Potassium Acetate, 
Potassium Bicarbonate, 
Potassium Bichromate, 
Potassium Bitartrate, 
Potassium Bromide, 
Potassium Carbonate, 
Potassium Chlorate, 
Potassium Citrate, 
Effervescent Potassium Citrate, 
Potassium Cyanide, 
Potassium and Sodium Tartrate, 
Potassium Ferrocyanide, 
Potassium Hypophosphite, 
Potassium Iodide, 
Potassium Nitrate, 
Potassium Permanganate, 
Potassium Sulphate, 
Solution of Potassa, 
Solution of Potassium Arsenite, 
Solution of Potassium Citrate, 
Troches of Potassium Chlorate, 



Official Latin Name. 
Potassa. 

Potassa Cum Calce. 
Potassa Sulphurata. 
Potassii Acetas 
Potassii Bicarbonas. 
Potassii Bichromas. 
Potassii Bitartras. 
Potassii Bromidum. 
Potassii Carbonas. 
Potassii Chloras. 
Potassii Citras. 
Potassii Citras Effervescens. 
Potassii Cyanidum. 
Potassii et Sodii Tartras. 
Potassii Ferrocyanidum. 
Potassii Hypophosphitum. 
Potassii Iodidum. 
Potassii Nitras. 
Potassii Permanganas. 
Potassii Sulphas. 
Liquor Potassee. 
Liquor Potassii Arsenitis. 
Liquor Potassii Citratis. 
Trochisci Potassii Chloratis. 



Potassa. KOH. This compound, better known as caustic 
potash, is, chemically speaking, potassium hydroxide or hydrate, 
obtained by decomposing a solution of potassium carbonate with 
milk of lime, evaporating the clear filtrate in perfectly clean iron or 
silver vessels until a small quantity of the liquid congeals upon 
cooling, and then pouring it into cylindrical moulds, whence the 
sticks are removed while still warm. 

The purity of the product obtained depends upon the quality of 
the potassium carbonate employed, and if made from the bicarbonate 
it is of much better quality. White caustic potash in sticks, labelled 
potassa by lime, is the kind generally used for pharmaceutical pur- 
poses, and should not contain over 5 or 6 per cent, of moisture ; com- 
mercial caustic potash is sometimes found to contain as much as 20 
or 25 per cent, of water. For chemical purposes potassa is purified 
by means of alcohol or baryta, being then known as potassa by alcohol 
or potassa by baryta. 



430 PHARMACEUTICAL CHEMISTRY. 

Potassa is a powerful caustic, very deliquescent, and rapidly ab- 
sorbs carbon dioxide from the air ; it must therefore be handled care- 
fully, and preserved in tightly stoppered bottles. 

The Pharmacopoeia requires that official potassa shall contain at 
least 90 per cent, of absolute potassium hydroxide, which is ascer- 
tained by titration with normal acid, each Cc. of which requires 
0.05599 Gm. KOH for neutralization. The official assay, requiring 
9 Cc. of y H 2 S0 4 for 0.56 Gm. of potassa, is only absolutely accurate 
in the absence of soda, as the latter, having a lower molecular weight, 
requires a relatively larger quantity of acid for saturation ; the small 
amount of soda permitted will not, however, materially affect the 
result, and may well be iguored. 

With a few exceptions the limits of impurities allowed by the 
Pharmacopoeia, in this and other compounds of potassium, rarely 
exceed J of 1 per ceut., and are usually determined vol u metrically. 
Since potassa readily absorbs carbon dioxide, as much as 1.38 per 
cent, of potassium carbonate is allowed in the official article, as shown 
by the test with lime-water; 5 Cc. of lime-water, containing about 
0.148 per cent., or 0.0074 Gm. of Ca(OH) 2 , are capable of precipi- 
tating 0.0138 Gm. of K 2 C0 3 , which is equal to 1.38 per cent, of 
1 Gm. of the sample. 

Besides slight traces of potassium silicate and nitrate, 1.5 per cent, 
of soda is also permitted in the official potassa, which is indicated 
by the quantity of normal potassium hydroxide solution necessary 
to cause an alkaline reaction in the nitrate obtained after precipi- 
tating all KOH present in 0.56 Gm. of the sample as acid potassium 
tartrate, by means of tartaric acid. Any soda present in the potassa 
will also have been converted into an acid tartrate, but will remain in 
solution, and, upon the addition of sufficient y KOH solution, be con- 
verted into normal double tartrate; 0.2 Cc. T KOH solution corre- 
sponds exactly to 0.008 Gm. NaOH, which is 1.5 per cent, of 0.56 
Gm., and the first drop added beyond this point should cause a 
permanent pink color, if it has not already appeared, showing an 
excess of alkali. 

Potassa with Lime. This preparation is a simple mechanical 
mixture of equal parts of potassa and lime, intended as a milder ap- 
plication than potassa alone. The object of mixing the ingredients 
in a warm mortar is to prevent the absorption of moisture, and, as 
the powder rapidly deteriorates upon exposure to air, it must be kept 
in tightly stoppered vials. Potassa with lime is also known as 
Vienna Caustic. It is rarely used. 

Sulphukated Potassa, or liver of sulphur, has been known for 
nearly 500 years, and for over 100 years has been made in the same 
manner as now officially prescribed. When potassium carbonate and 
sulphur are heated together, carbon dioxide is evolved and the sulphur 
unites with the potassium, forming polysulphides, a portion of which 



THE COMPOUNDS OF POTASSIUM. 431 

is oxidized to thiosulphate by the oxygen of the carbonate in excess 
over that passing off as carbon dioxide. Small quantities of potas- 
sium sulphate are also possibly formed, and, since high heat favors 
such a change, the temperature should be so regulated that the mass 
at no time shall assume a thin fluid condition, and that as little sul- 
phur as possible be consumed. If the preparation is carefully made, 
the following reaction is likely to occur : 3K 2 C0 3 + S 8 = 2K 2 S 3 -j- 
K 2 S 2 3 -f- 3C0 2 ; but with a higher heat potassium sulphate is formed 
from the thiosulphate. 

Sulphurated potassa is not a definite chemical compound, its com- 
position being variable and depending upon the care used in its 
manufacture. It must be protected against air and moisture to 
avoid further oxidation, which is indicated by a change in color from 
liver-brown to green and finally gray. 

The medicinal virtues of sulphurated potassa reside chiefly in the 
potassium sulphides present, the Pharmacopoeia demanding at least 
12.85 per cent, of sulphur in such combination, which may be de- 
termined by treatment with crystallized cupric sulphate. The 
following equation, CuSO 4 5H 2 + K 2 S 3 = CuS + S 2 + K 2 S0 4 + 
5H 2 0, shows that 248.8 parts of cryst. cupric sulphate require 31.98 
parts of sulphur for complete precipitation of the copper ; hence 1 
Gm., as prescribed in the official test, will require 0.1285 Gm. of 
sulphur, which is equivalent to 12.85 per cent, of the weight of sul- 
phurated potassa used. 

Potassium Acetate. KC 2 H 3 2 . This salt is prepared by neu- 
tralizing acetic acid with potassium carbonate or bicarbonate, the 
latter being preferable on account of its greater purity, evaporating 
the resulting solution to dryness, fusing the residue, and allowing the 
salt to solidify. The product, being very deliquescent, must be bot- 
tled while still warm, and should be well protected against air. 

The salt absorbs moisture very quickly when in contact wfth air, 
which it is impossible to prevent while weighing, hence only 98 per 
cent, of acetate is officially demanded. 

In order to determine the quality of organic salts of potassium 
volumetrically, it is necessary that they be first converted into carbo- 
nate by thorough ignition, the oxygen of the atmosphere aiding in 
the change. In the case of potassium acetate the following reaction 
occurs : 2 KC 2 H 3 2 + O s = K 2 C0 3 + 3H 2 -f 3C0 2 , two mole- 
cules, or 196 parts, of acetate furnishing one molecule, or 138 parts, 
of carbonate ; each Cc. of y H 2 S0 4 therefore required to neutralize 
the resulting carbonate in the official test represents 0.098 Gm., or 
10 per cent, of acetate ; for 138 : 196 : : 0.069 : 0.098. 

Potassium Bicarboxate. KHC0 3 . When carbon dioxide is 
passed into a concentrated solution of potassium carbonate, chemical 
union takes place, potassium bicarbonate or acid carbonate being 
formed according to the equation, K 2 C0 3 + H 2 + C0 2 = 2 KHC0 3 . 



432 PHARMACEUTICAL CHEMISTRY. 

The solution is afterward decanted from any separated silica, and 
crystallized. Potassium bicarbonate is permanent in the air, any 
hygroscopic tendency indicating contamination with carbonate ; this 
can be verified by adding to a solution of the salt barium chloride 
or magnesium sulphate, which are not precipitated by the pure bicar- 
bonate. The Pharmacopoeia admits slight traces of carbonate and 
chloride, also of iron. 

Potassium Bichromate, more properly Dichromate. K 2 Cr 2 7 . 
Although the official title of bichromate has been retained in the 
Pharmacopoeia, this is not in conformity with the chemical composi- 
tion of the salt. The term bichromate, according to accepted usage, 
would indicate a monobasic acid salt, requiring the formula KHO0 4 , 
a salt not known, whereas the official salt has the composition K 2 Cr 2 7 , 
showing it to be a compound of dichromic acid, H 2 Cr 2 7 . This acid 
may be looked upon as obtained by the union of two molecules of 
chromic acid with the elimination of water ; thus, H 2 Cr0 4 -f- H 2 Cr0 4 
= H 2 Cr 2 7 -f- H 2 0; or it may be assumed that chromic anhydride 
is capable of forming both chromic and dichromic acids ; thus, Cr0 3 
+ H 2 = H 2 Cr0 4 and 2 Cr0 3 + H 2 = H 2 Cr 2 7 . Dichromic acid 
may be said to be chromic acid holding chromic trioxide in solution, 
and is analogous to disulphuric, or fuming sulphuric, acid. 

Potassium dichromate is obtained by treating a solution of the 
chromate with sulphuric acid — thus, 2 K 2 Cr0 4 -f- H 2 S0 4 = K 2 Cr 2 7 
-f- K 2 S0 4 -j- H 2 — and separating the resulting salts by crystal- 
lization. The chromate is obtained direct from chrome-iron ore, 
FeOCr 2 3 , by roasting the same, in reverberatory furnaces, with 
potassium carbonate and chalk, the latter simply preventing fusion 
of the mixture, which is finally treated with water and strained to 
remove the iron. 

Potassium Bitartrate. KHC 4 H 4 6 . Acid potassium tartrate, 
or cream of tartar, as it is more familiarly known, is prepared for 
medicinal use by treating purified tartar with diluted hydrochloric 
acid for the purpose of removing the calcium tartrate present as 
chloride ; the mixture is heated and constantly agitated while cool- 
ing. Some tartaric acid and potassium bitartrate remain subse- 
quently in the mother-liquors, which are utilized in the manufacture 
of tartaric acid. 

Crude tartar, or argol, is obtained as a natural deposit in wine- 
casks, during the fermentation of grape-juice, and is purified by 
repeated treatment with water, clay, and animal charcoal to remove 
coloring-matters and other substances ; the filtered solution is crys- 
tallized, the resulting product still containing 5 to 15 per cent, of 
calcium tartrate as an impurity, which remains. 

The Pharmacopoeia permits a very slight admixture of calcium 
tartrate, less than 1 per cent., in the official article, but demands at 
least 99 per cent, of true acid potassium tartrate, which is determined 



THE COMPOUNDS OF POTASSIUM. 433 

by conversion into carbonate by means of ignition, as in the case of 
potassium acetate, and then titrating with normal acid. The follow- 
ing equations show that 376 Gm. of potassium bitartrate yield 138 
6m. of the carbonate, and that therefore each Cc. of f H 2 S0 4 must 

KHC 4 H 4 6 : 2KHC 4 H 4 6 + O 10 = 
K 2 CO a + H 2 S0 4 = K 2 S0 4 + C0 2 + 



correspond 


to 


0.18767 


Gm. 


K 9 C0 3 + 7 


Co 2 


-5H 2 


and 


H 2 0. 









While the second issue of the United States Pharmacopoeia for 
1890 directs the foregoing method of valuation for potassium bitar- 
trate, the first edition directed the assay to be made by titration of 
the free acid present with y KOH solution, each Cc. of which is 
capable of neutralizing 0.07482 Gm. of tartaric acid, and must 
therefore correspond to 0.18767 Gm. of true potassium bitartrate, 
because each molecule, or 149.61 Gm. of tartaric acid will yield one 
molecule, or 187.67 Gm., of the bitartrate, a mono-basic acid salt, 
which has one-half the saturating power of the pure acid. 

Much of the cream of tartar sold is of inferior quality and often 
largely adulterated, but there is no difficulty in procuring the official 
article if it is desired, as it is extensively manufactured in this 
country and abroad. 

The so-called soluble cream of tartar, or boro-tartrate of potas- 
sium and sodium, is officially recognized in the German Pharma- 
copoeia under the name tartarus boraxatus. It is soluble in its own 
weight of cold water, and is prepared by digesting 5 parts of potas- 
sium bitartrate in a solution of 2 parts of borax and 15 parts of 
water until dissolved ; the solution is evaporated to dryness, and the 
residue, while still warm, reduced to powder. 

Potassium Bromide. KBr. This well-known salt may be 
obtained by decomposing a solution of ferrous bromide with potas- 
sium carbonate, heating the mixture, filtering, evaporating the filtrate, 
and crystallizing. The process followed by large manufacturers is 
to add bromine to a solution of potassa until the liquid remains 
colored, evaporate it to dryness, and expose the saline residue, mixed 
with charcoal, in small portions at a time, to a red heat in an iron 
crucible ; the fused mass is treated with water, the resulting solutiou 
filtered and set aside to crystallize. When bromine and potassa are 
brought together, potassium bromide and bromate are formed ; thus, 
6KOH + Br 6 = oKBr + KBrO s + 8H 2 ; by heating the mixed 
salts with charcoal all bromate is reduced to bromide ; thus, KBr0 3 
+ C 3 = KBr -f- 3CO. 

The chief impurity likely to be encountered in potassium bromide 
is the chloride due to the chlorine present in bromine. The Phar- 
macopoeia demands the absence of more than 3 per cent, of chloride, 
which is ascertained volumetrically with decinormal silver nitrate 
solution. Since potassium chloride has a lower molecular weight 
(74.40) than the bromide (118.79), an equal weight of the same will 

28 



434 PHARMACEUTICAL CHEMISTRY. 

require a larger amount of silver solution for complete precipitation ; 
upon this the official test is based. 

The following rule will enable anyone to ascertain the exact per- 
centage of potassium chloride in any sample of bromide : Calculate 
how much j-q AgN0 3 solution will be required to precipitate a given 
weight of pure potassium bromide, and find also the quantity neces- 
sary to precipitate the same weight of pure potassium chloride. 
(Assuming that 0.5 Gm. of each salt be taken, it will require 42.09 
Cc. of the silver solution for the bromide, and 67.2 Cc. for the chlo- 
ride.) Subtract the lesser amount from the greater (67.2 — 42.09 = 
25.11), and the remainder will represent the difference for 100 per 
cent., or absolute purity. If this remainder be divided by 100 
(25.11-^-100 = 0.2511), the quotient will represent the quantity 
of y$ AgNO s solution necessary to indicate 1 per cent. Divide 
the quotient so obtained into the difference between the quantity 
of jq- AgN0 3 solution required for the given weight of a sample of 
bromide and for the same weight of pure bromide, the result will 
indicate the percentage of chloride in the sample. 

When potassium chromate is used as an indicator, no permanent 
red color, due to silver chromate, can appear in the official test until 
all bromide and chloride have been precipitated. Applying the 
above rule to the quantities of potassium bromide and silver solution 
prescribed by the Pharmacopoeia, 3 per cent, of chloride will be found 
indicated, as can be shown by the following calculations : 1 Cc. 
of T N o-AgN0 3 solution represents 0.011879 Gm. KBr or 0.00744 
Gm. KC1; for 169.55 parts of silver nitrate will completely precip- 
itate 118.79 parts of potassium bromide, or 74.4 parts of potassium 
chloride; therefore 0.5 Gm. KBr, if absolutely pure, will require 
42.09 Cc. of ^ AgN0 3 solution— for 0.5 -=- 0.011879 = 42.09, and 
0.5 Gm. KC1, if pure, require 67.20 Cc. of t N q- AgN0 3 solution — for 
0.5 -f- 0.00744 = 67 20; 67.20 — 42.09 = 25.11, and 25.11 -j- 100 
= 0.2511. Every 0.2511 Cc. of the silver solution used in excess 
of 42.09 Cc. for complete precipitation of 0.5 Gm. of potassium 
bromide will indicate 1 per cent, of chloride; now, 42.85 — 42.09 
= 0.76, and 0.76 -*- 0.2511 = 3. 

Potassium Cakbonate. K 2 CO s . This compound is familiarly 
known as salt of tartar, a name given to it because it was at one 
time prepared by ignition of tartar. It is now extensively prepared 
from potassium chloride by a method analogous to the Leblanc pro- 
cess for making sodium carbonate. The purer carbonate, such as is 
demanded by the Pharmacopoeia, is obtained by heating crystallized 
potassium bicarbonate to redness, whereby carbon dioxide and water 
are eliminated and potassium carbonate remains, the yield being 
about 68 or 69 per cent. The reaction is a very simple one, 
2KHCO ? = K 2 CO s + C0 2 + H 2 0. 

Potassium carbonate, on account of its very deliquescent nature, 
must be preserved in well-stoppered bottles, in a dry place. The 



THE COMPOUNDS OF POTASSIUM. 43o 

Pbarraacopceia demands an almost absolutely pure salt, 95 per ceut. 
of potassium carbonate being required and only slight traces of 
potassium chloride and iron permitted ; 3 to 4 per cent, of moisture 
is usually present. 

Potassium Chlorate. KC10 3 . At present potassium chlorate 
is probably chiefly made by a process similar to that given in the 
British Pharmacopoeia, which consists in passing chlorine gas into a 
moist mixture of potassium carbouate and slaked lime ; more water 
is subsequently added, the mixture boiled for a short time, and set 
aside to crystallize. The product is purified by recrystallization. 
The first reaction produces calcium hypochlorite aud chloride, the 
former being decomposed by heat into chlorate and chloride ; calcium 
chlorate then reacts with potassium carbonate, forming potassium 
chlorate and calcium carbonate. Leaving out the intermediate 
products, the reaction raav be expressed as follows : K 2 C0 3 — 
6Ca(OH) 2 - Cl 12 =2KC10 3 - 5CaCl 2 - CaC0 3 - 6H 2 0. 

Potassium chlorate is rarely found impure, and occurs in com- 
merce both in the form of crystals and fine powder ; two varieties 
are met with — the British and French. It is readily decomposed, 
often with explosive violence, when triturated with such substances 
as sugar, tannin, sulphur, etc. ; care is therefore necessary when such 
mixtures are to be dispensed. (See also page 356.) 

Potassium Citrate. K 3 C 6 H 5 7 — IT 2 0. This salt is prepared 
by neutralizing a solution of citric acid with potassium carbonate or 
bicarbonate, and evaporating the solution to dryness, with constant 
stirring, so as to obtain the salt in small granules. The finished pro- 
duct retains a little over 5J per cent, of water, but should be free from 
impurities; the commercial article is frequently acid, showing imper- 
fect saturation. As the salt is deliquescent, it must be well protected 
against air. 

In order to determine the quality of potassium citrate volumetri- 
cally, it is necessary to convert the salt into carbonate by ignition, 
and then to titrate with normal acid, as in the case of other organic 
potassium salts. Citric acid being tribasic, two molecules, or 648 
parts, of potassium citrate will yield three molecules, or 414 parts of 
carbonate; thus 2K 3 C 6 rT 5 7 H 2 - 1S = 3K 2 C0 3 - 9C0 2 - 7H 2 0; 
therefore, 1.08 Gm. ordered in the official test should yield 0.69 Gm. 
K 2 C0 3 , requiring 10 Cc. f HJSO,. 

Effervescent Potassium Citrate. The proportions of citric 
acid and potassium bicarbonate directed in the official formula for 
this preparation are exactlv right for forming a neutral citrate, as 
shown by the equation, H 3 C 6 H 5 7 H 2 - 3KHC0 3 = K 3 C, 3 H 5 7 - 
3C0 2 — 4H 2 G. Owing to the small amount of water of crystalliza- 
tion present in the citric acid, a slight reaction occurs upon triturat- 
ing the substances together, a pasty mass resulting, but complete 



436 PHARMACEUTICAL CHEMISTRY. 

reaction is not intended to take place until the finished preparation 
is dissolved in water. The prescribed temperature must not be ex- 
ceeded in drying the mass, so as to avoid fusion, coloration, and loss 
of carbon dioxide. It should be preserved in tightly stoppered 
bottles, in a dry place. 

Potassium Cyanide. KCN or KCy. This very poisonous 
compound is prepared on a large scale by exposing to red heat a 
mixture of dried potassium ferrocyanide and pure potassium carbon- 
ate, whereby potassium cyanide aud cyanate are formed, carbon diox- 
ide is eliminated, and metallic iron is precipitated ; the fused white mass 
is carefully decanted and allowed to solidify. The following equation 
explains the reaction which takes place : 2K 4 FeCy 6 -f- 2K 2 C0 3 = 
lOKCy -j- 2KCyO + Fe 2 + 2C0 2 . Potassium cyanate may be re- 
moved by means of alcohol or carbon disulphide. 

A purer product may be obtained by passing hydrocyanic acid gas 
iuto an alcoholic solution of potassa, when the newly formed cyanide 
will separate as a bulky crystalline precipitate, which may be washed 
on a filter with alcohol. 

In the official volumetric determination of potassium cyanide, ad- 
vantage is taken of the formation of a soluble double cyanide ot 
silver and potassium to indicate when one-half of the cyauogen pres- 
ent in a sample of potassium cyanide has combined with silver; 
hence, when a permanent precipitate of silver cyanide first appears, 
double the value is assigned to the silver solution used which it 
would possess if all the potassium cyanide were decomposed and pre- 
cipitated. In the official test each Cc. of y^ AgNO s solution repre- 
sents 0.013002 Gm. KCy, according to the equation, 2KCy + AgNO s 
= AgK(Cy) 2 + KN0 3 ; as soon as this point is passed, the follow- 
ing reaction occurs upon the addition of more silver solution, and a 
permanent precipitate appears: AgK(Cy) 2 -j- AgN0 3 =2AgCy -j- 
KN0 3 . The Pharmacopoeia demands that the official salt shall 
contain 90 per cent, of pure KCy. 

Potassium and Sodium Tartrate. KNaC 4 H 4 6 -j- 4H 2 0. 
This salt is commercially known as Rochelle Salt from the fact that 
it was first obtained at Rochelle, France, by an apothecary named 
Seignette, over two hundred years ago. It is prepared by neutraliz- 
ing the free acid in cream of tartar with sodium carbonate, whereby 
a normal double tartrate is produced ; the solution, which must be 
neutral, is boiled for a short time, filtered, concentrated, and set aside 
to crystallize, the crystals being afterward pulverized. According to 
the following equation, 2KHC 4 H 4 6 + (Na 2 C0 3 + 10H 2 O) = 
2(KNaC 4 H 4 6 4H 2 0) -f C0 2 + 3H 2 0, 8 parts of official cream of 
tartar will require about 6 parts of crystallized pure sodium carbonate, 
yielding about 1 2 parts of crystallized Rochelle salt. 

Potassium and sodium tartrate is recognized in the British Phar- 



THE COMPOUNDS OF POTASSIUM. 437 

niacopceia by the uame of soda tartarata, and in the German Phar- 
macopoeia as to /-tarns natronatus ; it is also known as sal Seignetti. 

Absolute purity is demanded for this salt by the Pharmacopoeia, 
which is determined by conversion into carbonate and titration with 
normal acid. Each molecule of potassium and sodium tartrate yields 
one molecule of the double carbonate, upon thorough ignition, as 
shown by the equation, KXaC 4 H 4 6 4H — 5 = KXaC0 3 — 
3C0 2 - 6H 2 0; hence 1 Cc. f H,S0 4 represents 0.141 Gm. of the 
crystallized salt. 

Potassium Feeeocyaxide. K 4 Fe(CX) 6 — 3H 2 0. Yellow prus- 
siate of potash possesses no medicinal properties, but is the source of 
official hydrocyanic acid and other cyanides ; when pure the salt is 
not poisonous. It is made by heating, in iron vessels, with constant 
stirring, a mixture of potassium carbonate, metallic iron, and scraps 
of horn, leather, or other nitrogen-bearing substances. The fused 
mass, known as " melt/' is, after cooling, leached with water, and 
the solution decanted and crystallized ; the insoluble residue consists 
of iron, charcoal, ferrous sulphide, calcium phosphate, and silica. 

AVhen chlorine is passed into a solution of potassium ferrocyanide, 
the ferricyanide, or red prussiate of potash, a valuable chemical re- 
agent, is produced, as shown bv the following equation, 2K 4 Fe(CX) 6 -f- 
Cl 2 = K 6 Fe 2 (CN) 12 or 2K 3 Fe(CX) 6 + 2KC1. 

Potassium Hyfofhosfhite. KH 2 P0 2 . Although this salt can 
be made by boiling phosphorus with solution of potassa, it is pre- 
ferably obtained by adding potassium carbonate to a solution of cal- 
cium hypophosphite, when calcium carbonate will be precipitated and 
potassium hypophosphite remain in solution, which can be recovered 
by filtering the mixture and carefully evaporating the filtrate on a 
water-bath, with constant stirring, until a granular salt results. The 
following equation shows the decomposition : Ca(H 2 PO.,) 2 — K 2 C0 3 
= 2KH 2 P0 2 - CaC0 3 . 

Potassium hypophosphite is very deliquescent, and must be pre- 
served in tightly stoppered bottles ; as it readily explodes when inti- 
matelv mixed with oxidizing agents, trituration with such substances 
must be avoided. 

The official salt is recjuired to contain at least 98.7 per cent, of 
pure KH 2 P0 2 , which is ascertained by titration with decinormal 
potassium permanganate solution in excess, and retitration of the 
excess with oxalic acid, as already explained under diluted hypo- 
phosphorous acid. The equation, 5KH. 7 PO., — 6H 2 S0 4 — 4KMn0 4 
=5KH 2 P0 4 - 2K 2 S0 4 - 4MnS0 4 - 6H 2 0, shows that each Cc. 
of yV KMn0 4 solution represents 0.0025977 Gm. KH 2 P0 2 ; heuce 
if 38 Cc. (40-2) are required for 0.1 Gm. of the salt, it must con- 
tain 98.7 per cent, of the pure hvpophosphite, for 38 X 0.0025977 
= 0.0937126, which is 98.7 per cent: of 0.1. 



438 PHARMACEUTICAL CHEMISTRY. 

Potassium Iodide. KI. When iodine is added to a solution 
of potassa the two substances combine, forming potassium iodide 
and iodate; thus, 6KOH + I 6 = 5KI + KI0 3 + SH 2 0. The pro- 
cess of manufacturing this salt is analogous to that given for potas- 
sium bromide, the iodate being reduced to iodide by heating with 
charcoal. 

Much of the commercial potassium iodide does not respond to the 
requirements of the Pharmacopoeia, as it occurs in white opaque 
crystals, which, having been obtained from an alkaline solution, are 
less pure; the official requirements demand practically total ab- 
sence of alkali, and such a salt crystallizes in colorless transparent 
cubes, but can also be obtained in the form of a white, granular 
powder. The pharmacopoeial test for the presence of potassium 
cyanide (due to cyanogen derived from the iodine) involves the for- 
mation of potassium ferrocyanide, which, reacting with ferrous sul- 
phate, rapidly produces a blue color, owing to the oxidizing effect of 
the air. Since each Cc. of y^ AgN0 3 solution represents 0.016556 
Gm. KI, 0.5 Gm. of an absolutely pure salt will require 30.25 Cc. 
for complete precipitation; if more than this quantity be required, it 
would indicate the presence of bromide or chloride. The Pharma- 
copoeia requires at least 99.5 per cent, of pure iodide, and hence 
states that 0.5 Gm. shall require not less than 30 nor more than 
30.25 Cc. of decinormal silver-nitrate solution. 

Potassium Nitrate. KN0 3 . The sources of this salt were at 
one time chiefly the natural deposits in India and extensive planta- 
tions in Europe and elsewhere for the artificial production of potas- 
sium nitrate by putrefaction of animal and vegetable matter in the 
presence of wood-ashes and calcareous earth. It is now largely 
obtained by mutual decomposition of potassium chloride and native 
sodium nitrate, advantage being taken of the lesser solubility of the 
newly formed sodium chloride to rid the solution of this impurity 
upon concentration by boiling. The potassium nitrate subsequently 
crystallizes out, and is further purified by re-solution and re-crystal- 
lization. 

Potassium nitrate is to be had both in the form of large crystals 
and as a fine granular powder; the latter is preferred for pharma- 
ceutical purposes, and is largely obtained from the manufacturers of 
gunpowder, who require a pure article for their purposes. 

The name saltpetre, or nitre, is used almost exclusively in com- 
merce, for this salt, and when fused and cast into round moulds it 
is sold under the name sal prunelle. 

Potassium Permanganate. KMn0 4 . In the manufacture of 
this compound the first step necessary is the production of potas- 
sium manganate, by heating to semi-fusion at a dull, red heat, an 
intimate mixture of manganese dioxide, caustic potassa, and potas- 
sium chlorate, when the following reaction occurs : 3Mn0 2 + 6KOH 



THE COMPOUNDS OF POTASSIUM, 439 

+KC10 3 =3K 2 Mn0 4 H-KCl+3H 2 0. The green, fused mass is then 
twice treated with boiling water, whereby the potassium manganate 
is converted into permanganate — 3K 2 Mn0 4 -j- 2H 2 = 2KMn0 4 
-fMn0 2 + 4KOH — manganese dioxide being again precipitated 
and potassium hydroxide remaining in solution with the perman- 
ganate. The presence of potassa in the liquid prevents a full yield 
of permanganate by holding a portion of the manganate in solution 
without change ; a stream of carbon dioxide is therefore passed into 
the liquid to neutralize the potassa and thus allow all the manganate 
to be converted into permanganate and dioxide ; in place of carbon 
dioxide, diluted sulphuric acid is sometimes used for the same pur- 
pose. Finally, after decantation and filtration through asbestos, the 
solution is concentrated and set aside to crystallize. As potassium 
permanganate is readily decomposed by organic matter, all dust and 
dirt must be excluded during the last steps of the process. 

The official method of valuation of potassium permanganate, by 
means of oxalic acid, depends upon the ready deoxidation of the 
salt by all reducing substances, two and one-half atoms of oxygen 
being liberated from each molecule of the permanganate. In the 
official test the oxalic acid is completely converted by oxidation into 
carbon dioxide and water, as shown by the following equation : 
5(H 2 C 2 O 4 +2H 2 O)+2KMnO 4 +3H 2 SO 4 =10CO 2 +K 2 SO 4 +2MnSO 4 
-}-18H 2 0, 628.5 parts of crystallized oxalic acid requiring 315.34 
parts of pure permanganate. The Pharmacopoeia demands potas- 
sium permanganate to be of 98.7 per cent, purity, 0.1 Gm. of which 
will oxidize 0.196717 Gm. of oxalic acid; or, in other words, 
0.196717 Gm. of crystallized acid will be required to discharge the 
red color of a solution containing 0.0987 Gm. KMn0 4 . Such a quan- 
tity of crystallized oxalic acid is contained in 31.3 Cc. of a deci- 
normal solution, for 0.196717-5-0.006285=31.3. 

Since potassium permauganate is very easily decomposed, it should 
never be triturated or dispensed with readily oxidizable or organic 
substances. Stains produced by the salt in mortars or on the hands 
are best removed with oxalic acid solution, either alone or with a 
little sulphuric acid. 

Potassium Sulphate. K 2 S0 4 . This salt, which, although 
rarely used in medicine or pharmacy, has been retained in the Phar- 
macopoeia, is obtained partly as a bi-product in many chemical opera- 
tions and partly from the mineral kainite, a natural potassium and 
magnesium sulphate. 

For a long time potassium sulphate, on account of the hardness of 
its crystals, was preferred as a diluent in the preparation of Dover's 
powder, and is still to-day used by some for this purpose. 

Solution of Potassa. The official Liquor Potassse can be made 
either by decomposition of a solution of pure potassium carbonate 
with milk of lime or by simple solution of 56 Gm. of potassa in 
944 Gm. of distilled water. Both methods are recognized in the 



440 PHARMACEUTICAL CHEMISTRY. 

Pharmacopoeia, the latter being generally preferred by pharmacists, 
as a matter of convenience, while the former is followed by manu- 
facturing chemists, for economical reasons. If simple solution of 
the potassa be employed, it is important that the percentage of KOH 
present be known, in order to insure a 5 per cent, solution ; the above 
proportions are calculated for 90 per cent, potassa and the proper 
quantity of a higher or lower grade can be readily found by the 
directions given in the Pharmacopoeia. Thus, if the potassa con- 
tains only 82 per cent. KOH, it will require 61 (5000-^-82) Gm. of 
potassa and 939 Gm. of distilled water, for 61 Gm. at 82 per cent, 
are equal to 56 Gm. at 90 per cent., 50 Gm. being the result in both 
cases and yielding 1000 Gm. of a 5 per cent, solution. 

The object, in the first process, of heating the bicarbonate in solu- 
tion until effervescence ceases, is to convert it into monocarbonate, 
and thus obtain a purer article than if commercial potassium car- 
bonate were used. By mixing the two liquids hot and boiling the 
mixture for ten minutes a more compact precipitate of calcium car- 
bonate is produced, which settles rapidly and from which the solution 
of potassa can be more readily separated. 

The process involves two simple reactions : 1. 2KHC0 3 =K 2 C0 3 
-fC0 2 +H 2 0; 2. K 2 C0 3 +Ca(OH) 2 =2KOH+CaC0 3 . Lime is 
used in excess of the theoretical requirement on account of its slight 
solubility, and experience has also taught that considerable dilution 
of the two liquids is necessary, as the reaction cannot be completed 
in concentrated solutions. 

In order to preserve the quality of solution of potassa it is essen- 
tial that it be kept in securely stoppered bottles, to avoid absorptiou 
of carbon dioxide; the bottles should be made of green glass, as flint 
ware is easily acted upon, and the stoppers should be thinly coated 
with paraffin or petrolatum, to prevent their becoming " fixed. " 
Solution of potassa should never be filtered through paper, which 
is rapidly attacked by the alkali ; large volumes are best decanted 
or siphoned from any sediment, while small quantities may be con- 
veniently filtered through glass-wool or asbestos. 

The official solution of potassa has a specific gravity of about 1.036 
at 15° C. (59° F.), and should contain about 5 per cent, of potas- 
sium hydroxide, which is equal to about 27 grains in each fluidounce ; 
its strength is determined volumetrically with normal acid, each Cc. 
of which corresponds to 0.05599 Gm. KOH. 

Solution of Potassium Aesenite. This preparation can be 
more conveniently studied in connection with the preparations of 
arsenic. 

Solution of Potassium Citrate. The Pharmacopoeia very 
properly directs the extemporaneous preparation of this solution, as 
it does not keep well and soon loses its refreshing taste. The pro- 
portions of citric acid, 6 Gm., and potassium bicarbonate, 8 Gm., in 
the official formula show a slight excess of citric acid over the quan- 



THE COMPOUNDS OF POTASSIUM. 441 

tity necessary to form a neutral salt, which improves the flavor of 
the finished product. The solution contains 8.16 Gm. of potassium 
citrate and 0.4 Gm. of citric acid in 100 Cc, besides some carbonic 
acid, which corresponds to about 38 grains of the salt in each fluid- 
ounce. 

Although the Pharmacopoeia has given the synonym, mistura 
potassii citratis, to this solution, it differs from the preparation for- 
merly recognized by that name and more familiarly known as neutral 
mixture. The former preparation was made by neutralizing fresh 
lemon-juice, strained through cotton, with potassium bicarbonate, and 
possessed, therefore, a more agreeable flavor, although of uncertain 
strength. Some physicians still prefer the old neutral mixture to 
the present official solution in many cases. 

Besides the potassium salts officially recognized, the following are 
occasionally used in medicine and pharmacy. 

Potassium Benzoate. KC 7 H 5 2 -f 3H 2 0. This salt can be 
most conveniently obtained by adding benzoic acid to a solution of 
potassium bicarbonate and evaporating the resulting solution ; 100 
parts of benzoic acid require 82 parts of potassium bicarbonate for 
complete neutralization, yielding 175.5 parts of a salt having the 
above composition. 

Potassium Chloride. KC1. This may be obtained as a by- 
product in the manufacture of other salts, but is chiefly derived from 
the mineral carnallite, a double potassium and magnesium chloride, 
extensively mined in Germany. 

Potassium Salicylate. 2KC 7 H 5 3 -f-H 2 0. This can be readily 
prepared in the manner outlined for potassium benzoate, simply using 
salicylic acid in place of benzoic acid, 100 parts of the former re- 
quiring 72.5 parts of potassium bicarbonate and yielding 127.5 parts 
of the newly formed salt. 

Potassium Sulphite. K 2 S0 3 +2H 2 0. When sulphur dioxide 
is passed into a solution of potassium carbonate until the carbon di- 
oxide has all been expelled and another portion of potassium car- 
bonate equal in weight to that first used is then added, potassium 
sulphite will crystallize on concentration of the solution. If, in place 
of more potassium carbonate, strong alcohol be added to the solution 
carrying sulphur dioxide in excess, potassium bisulphite, KHSO s , 
will crystallize out. 

Potassium Tartrate. K 2 C 4 H 4 6 +H 2 0. Normal potassium 
tartrate is made from the bitartrate by neutralizing the excess of acid 
present with potassium carbonate. The salt was dropped at the last 
revision of the U. S. Pharmacopoeia, but is still recognized in the 
British and German Pharmacopoeias. 



CHAPTEK XLI 



THE COMPOUNDS OF SODIUM. 



The official salts of sodium resemble those of potassium in many 
respects and are frequently prepared by aualogous processes. Twenty- 
one salts, besides four liquid and three solid preparations, are recog- 
nized in the Pharmacopoeia, as follows : 



Official English Name. 
Soda, 

Sodium Acetate, 
Sodium Arsenate, 
Sodium Benzoate, 
Sodium Bicarbonate, 
Sodium Bisulphite, 
Sodium Borate, 
Sodium Bromide, 
Sodium Carbonate, 
Dried Sodium Carbonate, 
Sodium Chlorate, 
Sodium Chloride, 
Sodium Hypophosphite, 
Sodium Hyposulphite (Thiosulphate), 
Sodium Iodide, 
Sodium Nitrate, 
Sodium Nitrite, 
Sodium Phosphate, 
Sodium Pyrophosphate, 
Sodium Salicylate, 
Sodium Sulphate, 
Sodium Sulphite, 
Sodium Sulphocarbolate, 
Solution of Soda, 
Solution of Chlorinated Soda, 
Solution of Sodium Arsenate, 
Solution of Sodium Silicate, 
Troches of Sodium Bicarbonate, 



Official Latin Name. 
Soda. 

Sodii Acetas. 
Sodii Arsenas. 
Sodii Benzoas. 
Sodii Bicarbonas. 
Sodii Bisulphis. 
Sodii Boras. 
Sodii Bromidum. 
Sodii Carbonas. 
Sodii Carbonas. Exsiccatus. 
Sodii Chloras 
Sodii Chloridum. 
Sodii Hypophosphis. 
Sodii Hyposulphis. 
Sodii Iodidum. 
Sodii Nitras. 
Sodii Nitris. 
Sodii Phosphas. 
Sodii Pyrophosphas. 
Sodii Salicylas. 
Sodii Sulphas. 
Sodii Sulphis 
Sodii Sulphocarbolas. 
Liquor Sodse. 
Liquor Sodae Chloratse. 
Liquor Sodii Arsenatis. 
Liquor Sodii Silicatis. 
Trochisci Sodii Bicarbonatis. 



Soda. NaOH. The usual method of manufacture of sodium 
hydroxide, or caustic soda, is by decomposition of a solution of sodium 
carbonate by means of milk of lime, the filtrate, as in the case ot 
potassa, being evaporated in silver or iron vessels, and finally allowed 
to congeal in suitable moulds. The product thus obtained is known 
as soda by lime. A purer article may be obtained either by direct 
action of metallic sodium on water or by purification of commercial 
soda with alcohol. 

Like caustic potash, caustic soda is very deliquescent, and rapidly 
absorbs carbon dioxide upon exposure to the air; hence the same care 



THE COMPOUNDS OF SODIUM. 443 

must be observed in its preservation in tightly stoppered green-glass 
bottles. 

The Pharmacopoeia makes similar requirements for soda as for 
potassa, in regard to the allowable limit of impurities, and also 
demands that official socla shall contain not less than 90 per cent, of 
absolute NaOH, which is volumetrically determined with normal 
acid, each Cc. of which is capable of neutralizing 0.03996 Gm. 
NaOH. 

Sodium Acetate. NaC 2 H 3 2 -f 3H 2 0. This salt may be prepared 
by neutralizing acetic acid with sodium carbonate or bicarbonate, 
concentrating the resulting solution and crystallizing ; in a crude 
form it is extensively obtained in the manufacture of acetic acid, and 
may be purified by roasting and other processes. Sodium acetate 
differs from potassium acetate in containing nearly 40 per cent, of 
water of crystallization, and in its stability upon exposure to air, 
hence less care is necessary in its preservation ; it is about one-third 
as soluble in water and far less soluble in alcohol than the potas- 
sium salt. 

The valuation of the so-called organic sodium salts is performed, 
as in the case of the corresponding potassium salts, byconversion into 
carbonate and subsequent titration with acid. The following equa- 
tion, 2(NaC 2 H 3 2 -f 3H 2 0) + 8 = Na 2 C0 3 + 3C0 2 + 9H 2 0, shows 
that two molecules, or 271.48 parts, of crystallized sodium acetate 
yield, upon complete ignition, one molecule, or 105.85 parts, of an- 
hydrous sodium carbonate; hence, each Cc. of f- H 2 S0 4 , neutralizing 
0.052925 Gm. Na 2 CO s , corresponds to 0.13574 Gm. NaC 2 H 3 2 + 
3H 2 0. The Pharmacopoeia demands that the official sodium acetate 
shall be 100 per cent, pure, and 1.36 Gm. of the salt must, therefore, 
after complete ignition, require 10 Cc. of normal acid to neutralize 
the alkaline residue, as stated in the official test. 

Sodium Arsenate. Na 2 HAs0 4 -j- 7H 2 0. The official salt, as 
shown by the chemical formula, is disodium orthoarsenate, and 
bears a close analogy to the official sodium phosphate; the exact com- 
position must depend upon the proportions of the ingredients used 
in its manufacture. Sodium arsenate is usually obtained by fusing 
together, at a red heat, arsenous oxide, dried sodium carbonate, and 
sodium nitrate ; effervescence ensues, and, when complete quiet fusion 
has set in, the residue will consist of sodium pyroarsenate, as shown 
by the following equation : As 2 3 + 2NaN0 3 + Na 2 C0 3 = Na 4 As 2 7 
-j- N 2 3 -}- CO, 2 . The fused mass, having been poured on a stone 
slab and allowed to solidify, is dissolved, while still warm, in water, 
whereby the sodium pyroarsenate is converted into orthoarsenate by 
the appropriation of water, thus, Na 4 As 2 7 -j- H 2 = 2Na 2 HAs0 4 . 
The solution is set aside to crystallize, when a salt containing 40.4 
per cent, of water, and having the above formula, will be obtained. 

The British Pharmacopoeia directs the following proportions : 



444 PHARMACEUTICAL CHEMISTRY. 

Arsenous oxide 10 parts, sodium nitrate 8J parts, and dried sodium 
carbonate 5J parts ; if an excess of sodium carbonate be used, tri- 
sodium arsenate, Na 3 As0 4 , will be formed, while an excess of arsenic 
acid yields monosodium arsenate, NaH 2 As0 4 . 

The official salt, upon exposure to dry air, gradually loses a por- 
tion of its water of crystallization until a salt of the composition 
Na 2 HAs0 4 + 2H 2 remains, containing only 16.2 per cent, of water, 
hence, it should be preserved in tightly stoppered bottles. 

Sodium Benzoate. NaC 7 H 5 2 . This salt may be conveniently 
prepared by suspending benzoic acid in hot water and slowly adding 
sufficient sodium bicarbonate to form a neutral solution, which is 
then filtered and evaporated, with frequent stirring, on a water-bath, 
to dryness. 100 parts of benzoic acid require about 70 parts of 
official sodium bicarbonate and yield about 118 parts of sodium 
benzoate. The salt can also be obtained in crystalline form, having 
the composition NaC 7 H 5 2 -f- H 2 ; but, as it effloresces readily, the 
Pharmacopoeia has recognized only the anhydrous salt. 

The valuation of sodium benzoate is made, like that of the acetate, 
by ignition and titration of the resulting sodium carbonate with nor- 
mal acid. The equation, 2NaC 7 H 5 2 + O 30 = Na 2 C0 3 +5H 2 -f 
13C0 2 , shows that 287.42 parts of sodium benzoate will yield 105.85 
parts of anhydrous sodium carbonate, therefore each Cc y H 2 S0 4 
represents 0.1437 1 Gm. NaC 7 H 5 0,. Using 2 Gm. of the salt, as 
directed in the official test, 13.0 Cc. T H 2 S0 4 will be required to 
neutralize the alkaline residue if 99.8 per cent. NaC,H 5 2 be present, 
for 99.8 per cent, of 2 is 1.996 and 0.1437 X 13.9 = 1.997. 

Sodium Bicarbonate. NaHC0 3 . This well-known compound 
is manufactured on a large scale by different processes. If sodium 
carbonate in crystalline form be treated with carbon dioxide, anhy- 
drous sodium bicarbonate, or acid carbonate, will be formed and water 
eliminated ; thus, (Na 2 CO s + 10H 2 O) + C0 2 = 2NaHCO s + 9H 2 ; 
by using a mixture of anhydrous and crystallized sodium carbonate, 
a part of the eliminated water will be required for converting the 
former into bicarbonate, the balance being allowed to escape by 
drainage. Sodium bicarbonate is also obtained as an intermediate 
product in the manufacture of the normal carbonate by the Solvay 
ammonia-soda process, wherein concentrated solution of sodium 
chloride is mixed with ammonia and then saturated with carbon 
dioxide under pressure. Sodium bicarbonate is precipitated and am- 
monium chloride remains in solution. In either case the newly 
formed sodium bicarbonate is washed with small quantities of water 
for the purpose of removing the more soluble impurities. 

The product of the Solvay process requires more careful purifica- 
tion, owing to contamination with ammonium salts, especially am- 
monium carbonate, hence sodium bicarbonate, prepared from normal 
carbonate, is preferred for medicinal purposes. 



THE COMPOUNDS OF SODIUM. 445 

Commercial sodium bicarbonate is frequently contaminated with 
carbonate and chloride, but if a pure salt is wanted, this may be 
readily obtained by percolating the commercial article with cold dis- 
tilled water and drying the purified residue with moderate heat only. 

The Pharmacopoeia does not require absolute purity for sodium 
bicarbonate, traces of carbonate, chloride, sulphate, and sulphite 
being permitted. The official salt must, however, contain at least 
98.6 per cent. NaHC0 3 , as indicated by the demand that 0.85 Gm. 
of the salt shall require not less than 10 Cc. J H 2 S0 4 for complete 
neutralization, each Cc. representing 0.08385 Gm. NaHC0 3 . 

Sodium Bisulphite. NaHS0 3 . This salt, known also as acid 
sodium sulphite, is rarely used in medicine. It is prepared by passing 
sulphur dioxide into a solution of sodium carbonate to saturation 
and until all carbon dioxide has been expelled, the reaction being as 
follows: Na 2 C0 3 +H 2 0+2S0 2 =2NaHS0 3 -|-C0 2 . The solution is 
then concentrated and allowed to crystallize. 

Sodium bisulphite is not a very stable compound, and upon ex- 
posure to air is gradually oxidized and converted into sulphate, 
sulphur dioxide being given off at the same time. Traces of sulphate 
and chloride are permitted in the official salt. The turbidity caused 
in a solution of the salt by addition of hydrochloric acid, indicating 
the presence of thiosulphate (hyposulphite), is due to finely precipi- 
tated sulphur. 

The Pharmacopoeia demands at least 90 per cent, of absolute 
NaHS0 3 in the official compound, which is determined volumetrically 
by means of iodine, the latter acting as an oxidizing agent, converting 
the acid sulphite into an acid sulphate; thus, NaHS0 3 -j-I 2 H-H 2 0= 
NaHS0 4 -f 2HI, Since 103.86 parts of the acid sulphite require 
253.06 parts of iodine for complete oxidation, each Cc. ^ I solution 
containing 0.012653 Gm. of iodine is capable of oxidizing 0.005193 
Gm. NaHS0 3 and 45 Cc. will be required to indicate 90 per cent, 
if 0.26 Gm. of the salt be used for the assay, as directed, for 90 per 
cent, of 0.26 is 0.234 and 0.005193x45=0.2336-}-. jS t o permanent 
blue tint, due to formation of iodized starch, will occur until all 
sulphurous acid has been oxidized. 

Sodium Borate. Na 2 B 4 O 7 +10H 2 O. The more familiar name 
borax is usually applied to this compound, which, although some- 
times called sodium biborate, is, as shown by the chemical formula, 
sodium tetraborate or pyroborate. It is found extensively in different 
parts of the world, particularly in California, where immense quan- 
tities are obtained from the blue mud of certain lakes. Solution and 
recrystallization are resorted to for the purpose of purification. Con- 
siderable quantities of borax are also obtained from crude boric acid, 
by treating it with sodium carbonate, and from various minerals 
containing borates of sodium, calcium, and magnesium. 

Borax is of special interest in pharmacy on account of its peculiar 



446 PHARMACEUTICAL CHEMISTRY. 

behavior with other substances. It is incompatible with mucilage of 
acacia, causing gelatinization, which can, however, be prevented by 
the presence of sugar ; it precipitates many alkaloids from their 
solution, such as cocaine, morphine, atropine, quinine, etc., except 
in the presence of glycerin ; it forms a damp, almost moist, mixture 
when triturated with alum ; in the presence of glycerin it decomposes 
alkali bicarbonates with effervescence; and, lastly, while an aqueous 
solution of borax shows an alkaline reaction toward litmus, a solution 
in glycerin has a decided acid reaction, which is changed to alkaline 
upon large dilution with water. This last behavior is also observed 
with other bodies resembling glycerin, such as mannitol, glucose, etc. 

Sodium Bromide. NaBr. This salt is prepared in a manner 
similar to potassium bromide, either by decomposing a solution of 
ferrous bromide with sodium carbonate or by treating a solution of 
soda with bromine and finally reducing any sodium bromate formed 
with charcoal. 

Sodium bromide is somewhat hygroscopic, but the Pharmacopoeia 
has fixed the limit of moisture at 3 per cent. As in the case of the 
corresponding potassium salt, some chloride is usually present, which 
is volumetrically determined with decinormal silver nitrate solution, 
each Cc. of which is equivalent to 0.010276 Gm. NaBr or 0.005837 
Gm. NaCl. The rule given under potassium bromide (page 434) may 
be used for finding the exact percentage of sodium chloride contained 
in any sample. The Pharmacopoeia requires 97.29 per cent, of pure 
XaBr in the dry salt by demanding that not more than 29.8 Cc. 
^y AgN0 3 solution shall be necessary to precipitate completely 0.3 
Gm. of the salt. This would indicate about 2.76 per cent. NaCl, 
for 0.3 Gm. of pure NaBr require 29.19 Cc. ^ T AgN0 3 solution, and 
each 0.221 Cc. used in excess of that quantity indicates 1 per cent. 
NaCl; then 29.8— 29.19=0.61 and 0.61-^0.221=2.76. 

Sodium Carbonate. ^N~a 2 C0 3 -f 10H 2 O. Three distinct pro- 
cesses are in use at the present day for the manufacture of this salt, 
namely, the Leblanc process of 1784, the cryolite process of 1851, 
and the Solvay ammonia process of 1873. In both the Leblanc and 
Solvay processes sodium chloride is employed as the starting-point. 
In the first case sodium chloride is converted into sodium sulphate 
by action of sulphuric acid, and then into sodium sulphide, and sub- 
sequently carbonate, by treatment with coal and chalk, calcium sul- 
phide occurring as a waste product. In the ammonia process a 
solution of sodium chloride is treated with ammonia gas and carbon 
dioxide under pressure, when acid sodium carbonate and ammonium 
chloride are produced, together with some acid ammonium carbonate, 
which reacts with more sodium chloride, converting it into sodium 
bicarbonate. Finally the sodium bicarbonate is converted by heat 
into the normal carbonate. 

The cryolite process consists in heating the powdered mineral 



THE COMPOUNDS OF SODIUM. 447 

cryolite, a double sodium aud aluminum fluoride (AlF 3 3NaF), with 
chalk or limestone, whereby a soluble sodium aluminate and insoluble 
calcium fluoride are produced, carbon dioxide being eliminated. By 
passing carbon dioxide under pressure into a solution of the sodium 
aluminate sodium carbonate is formed, as well as aluminum hydroxide, 
the latter being precipitated. This process is extensively employed 
in this country, large quantities of cryolite being brought from Green- 
land. 

In each of the three processes the sodium carbonate formed is 
brought into solution, which is filtered, concentrated, and allowed to 
crystallize. The various steps in the manufacture of the salt can be 
conveniently shown by the following equations : 

1. The Leblanc Process : 

a. NaCl + H 2 S0 4 -=NaHS0 4 -fHCl. 

b. NaHS0 4 +]S T aCl=Na 2 S0 4 +HCl. 

c. ]N T a 9 S0 4 +C 4 =Na 2 SH-4CO. 

d. Na;S+CaC0 3 =Na a C0 3 +CaS. 

2. The Solvay Process: 

a. NaCl + 2NH 3 -f-3C0 2 -f-2H 2 0=NaHC0 3 -f NH 4 HCO s + 

NH 4 C1. 

b. NaCl+NH 4 HC0 3 =NaHC0 3 +NH 4 Cl. 

c. 2^HC0 3 =Na 2 C0 3 +C0 2 -j-H 2 0. 

3. The Cryolite Process : 

a. Na 3 AlF 6 4-3CaC0 3 =Na 3 A10 3 +3CaF 2 + 3C0 2 . 

b. 2Na 3 A10 3 +3C0 2 -[-3H 2 0=3Na 2 C0 3 +2Al(OH) 3 . 

The official sodium carbonate contains 63 per cent, of water, but 
effloresces upon exposure to dry air, being gradually converted into a 
white powder. The crystallized salt is rarely used in medicine. The 
commercial salt is usually contaminated with chloride and sulphate, 
and is purified by recrystallization. The Pharmacopoeia requires that 
the anhydrous salt, deprived of all water by heating immediately 
before being weighed, shall contain at least 98.9 per cent, of Na 2 C0 3 , 
as ascertained by titration with normal acid. The following equa- 
tion, Na 2 CO s +H,S0 4 =Na 2 SO 4 +CO,-f-H 2 O, shows that each Cc. 
£H 2 S0 4 corresponds to 0.052925 Gm. absolute Na,C0 3 , hence 18.7 
Cc. will represent 0.989 Gm. in the official test. 

Dried Sodium Carbonate. This preparation is recognized in 
the Pharmacopoeia partly with a view of supplying a more uniform 
product than the crystallized salt and partly for convenience in dis- 
pensing. By following the official directions a part of the water of 
crystallization is allowed to pass off* at room temperature, by efflor- 
escence, to avoid fusion of the salt at a higher temperature, after 
which the white powder is reduced to a definite weight by exposure 
to a moderate heat, the final residue still retaining about 26 per cent, 
of water, and probably corresponding in composition to the formula 
Na 2 C0 3 -f 2H 2 0. In this condition sodium carbonate is somewhat 
hygroscopic and must be preserved in'tightly stoppered bottles. The 



448 PHARMACEUTICAL CHEMISTRY. 

official article should contain about 73 per cent, of absolute Na 2 C0 3 . 
The British Pharmacopoeia requires an absolutely anhydrous salt. 

Sodium Chlorate. NaC10 3 . This salt may be prepared in a 
similar mauner to potassium chlorate or by decomposing a solutiou 
of acid sodium tartrate or sodium silicofluoride with potassium 
chlorate (NaHC 4 H 4 6 -f KClOs^NaClOg+KHC^H^or Na 2 8iF a + 
2KC10 3 =2NaCl-f-K 2 SiF 6 ), removing the precipitated potassium 
compound by filtration, concentrating the solution, and allowing the 
chlorate to crystallize. 

Sodium chlorate is vastly more soluble in both water and alcohol 
than the corresponding potassium salt ; but, like the latter, is readily 
decomposed when triturated with organic or other easily oxidizable 
substauces, hence must be haudled with care. 

Sodium Chloride. NaCl. There is probably no substauce so 
universally distributed over the world as common salt, nature pro- 
viding it both in crystalline form, as rock-salt, or in solution, as sea- 
water and the brine of salt wells. Rock-salt is extensively mined, 
but the largest supply of salt is obtained by evaporation of the natural 
solutions. 

Sodium chloride is employed in the manufacture of certain chemi- 
cals, but is used rarely in medicine, although an indispensable requi- 
site in the animal system. It is of chief interest to pharmacists as 
a reagent in the volumetric valuation of silver salts. 

Sodium Hypophosphite. NaH 2 P0 2 -f H 2 0. Like the corre- 
sponding potassium salt, this salt may be conveniently made by de- 
composing a solution of calcium hypophosphite with sodium carbonate 
or sulphate. After removal of the calcium salt by filtration the 
solution is evaporated on a water-bath to dryness, with constant 
stirring for the purpose of granulation. 

Sodium hypophosphite is hygroscopic, but more permanent than 
the potassium salt upon exposure to air, and explodes readily when 
triturated with nitrates, chlorates, or permanganates, owing to its 
tendency to oxidation. 

The Pharmacopoeia requires the official salt to contain not less 
than 97.96 per cent, of pure NaH 2 P0 2 , to be ascertained by titration 
with decinormal potassium permanganate solution. An excess of 
the reagent is added and the excess determined with oxalic acid 
solution, as explained under potassium hypophosphite. The equation 
5(NaH 2 P0 2 +H 2 0) + 6H 2 S0 4 + 4KMn0 4 =5NaH 2 P0 4 +2K 2 S0 4 + 
4MnS0 4 -f 11H 2 shows that 5 molecules or 529.2 parts of pure 
crystallized sodium hypophosphite require 4 molecules, or 630.68 
parts, of potassium permanganate for complete oxidation ; hence 
1 Cc. t n q KMn0 4 solution represents 0.002646 Gm. NaH 2 P0 2 -j-H 2 0. 

Sodium Iodide. Nal. This salt may be prepared by adding 
iodine to a solution of caustic soda ; but, since, on the reduction of 



THE COMPOUNDS OF SOD I CM. 449 

the resulting sodium iodate with charcoal, some sodium carbonate is 
apt to be formed, it is preferable to obtain the salt by double decom- 
position of ferrous or ferroso-ferric iodide with sodium carbonate. 
The reaction takiug place in either case may be explained by the 
following equations : Fel, - (Xa,CO 3 -j-10H.,O) = 2NaI-f FeC0 3 + 
10H 2 O; Fe 3 I 8 +4(Xa 2 CO 3 ^10H 2 O)=8NaI-4CO 2 +Fe 3 (OH) 8 -f 
36H 2 0. The mixture is boiled so as to facilitate separation of the 
iron compound by filtration, after which the filtrate is evaporated 
to dryness, with constant stirring, thus yielding a finely granulated 
salt. 

Sodium iodide crystallizes, in an anhydrous state, at temperatures 
above 40° C. (104° F.), and this is the salt recognized by the Pharma- 
copoeia ; but at ordinary temperatures it takes up nearly 19.5 per 
cent, of water, and then has the composition Nal-f 2H 2 ; the latter 
salt is decidedly less hygroscopic than the official anhydrous salt, 
which readily absorbs moisture from the air. This fact explains the 
very marked development of heat when strong solutions of the an- 
hydrous salt are made, due to a chemical union of the salt with water, 
whereas similar solutions of potassium iodide produce a decided reduc- 
tion of temperature. The Pharmacopoeia requires the absence of 
more than 5 per cent, of water, which may be due to the presence 
of hydrated crystals or may have been absorbed by the anhydrous 
salt. 

Sodium iodide, as well as its aqueous solution, gradually undergoes 
decomposition upon exposure to light, becoming colored, hence both 
should be preserved in dark amber-colored bottles. 

The official salt must contain not less than 98 per cent, of pure 
sodium iodide, as indicated by the demand that 0.5 Gm. of the 
well-dried salt shall require not less than 33.4 nor more than 34.5 
Cc. yu AgN0 3 for complete precipitation. 0.5 Gm. of absolute Nal 
requires exactly 33.4 Cc, and any increase above this may be due to 
sodium bromide and chloride present, since both of these salts have 
a lower molecular weight than the iodide, and, consequently, require 
a greater relative amount of silver solution for precipitation. 

Sodium Nitrate. NaN0 3 . The immense nitre-beds of Chili 
and Peru furnish this salt in a more or less crude state ; it is com- 
mercially known as Chili saltpetre, or cubic nitre, and is purified 
by repeated solution and crystallization. 

Sodium nitrate is of comparatively little interest in pharmacy, but 
is extensively employed in the manufacture of nitric and sulphuric 
acids, potassium nitrate, etc. It differs from ordinary saltpetre in 
being hygroscopic and in its greater solubility in water and alcohol. 

Sodium Nitrite. NaN0 2 . This salt is interesting chiefly as the 
source of nitrous acid in the official process for the manufacture of 
ethyl nitrite in the preparation of spirit of nitrous ether. When 
sodium nitrate is heated with charcoal, starch, or similar reducing 

29 



450 PHARMACEUTICAL CHEMISTRY. 

agents, sodium nitrite is formed ; but a better process consists in 
heating fused sodium nitrate for some time with lead in thin sheets, 
whereby the lead is gradually converted into lead oxide or litharge 
and the sodium salt is reduced to nitrite; thus, 2NaN0 3 +Pb 2 = 
2NaN0 2 +2PbO. The fused mass is lixiviated with water, the 
solution treated with carbon dioxide to remove any lead possibly 
held in solution, filtered, and finally allowed to crystallize. By 
repeated recrystallization a very pure salt can be obtained containing 
98 per cent, and over of absolute sodium nitrite. 

On account of its deliquescent character and ready oxidation to 
nitrate upon exposure to air, the salt must be carefully preserved in 
tightly closed bottles. 

The value of sodium nitrite depends upon the proportion of NaN0 2 
present, which should be not less than 97.6 per cent., and is de- 
termined by measuring the volume of nitrogen dioxide (N 2 2 or NO) 
obtainable from a given weight of the salt. Whenever sodium 
nitrite is brought together with potassium iodide and diluted sul- 
phuric acid, nitrogen dioxide and iodine are liberated with the for- 
mation of sodium and potassium acid sulphates ; by conducting the 
operation in special apparatus, permitting of the collection of the 
gas in a graduated tube, its volume can readily be measured, and 
from this the corresponding weight of sodium nitrite be calculated. 

The equation, NaN0 2 + KI + 2H 2 S0 4 = NO+ 1+ NaHS0 4 + 
KHS0 4 -|-H 2 0, shows that one molecule, or 68.93 Gm. of absolute 
NaN0 2 yields one molecule, or 29.97 Gm. of NO gas: but, since 
the gas is to be measured, it is necessary to ascertain the weight of 
a cubic centimeter of the same. It is well known that a liter of 
hydrogen weighs 0.0896 Gm. ; hence a liter of any other gas must 
weigh as many times 0.0896 Gm. as the gas is heavier than hydro- 
gen ; nitrogen dioxide is 14.985 times as heavy as hydrogen, for 
equal volumes of the two gases weigh 2 and 29.97 respectively • a 
liter of NO gas must therefore weigh 14.985 times 0.0896 Gm. or 
1.34256 Gm., which, divided by 1000, gives 0.00134256 Gm. as 
the weight of one cubic centimeter. But this weight is based on 
standard conditions — namely, a temperature of 0° C. (32° F.) and a 
barometric pressure of 760 Mm., and any change in these conditions 
must change the weight of a Cc. of gas. Gases are known to in- 
crease in volume to the extent of -^t^ or 0.003663 for every 1° C., 
or 1.8° F., hence the weight of a Cc. of gas at any higher tempera- 
ture can be ascertained by dividing the weight of it at 0° C. (32° 
F.) by the increased volume at the higher temperature; at 15° C. 
(59° F.), 1 Cc. of any gas at 0° C. has increasesd to 1 +(0.003663 X 15) 
or 1.054945 Cc, and at 25 C. (77° F.) to 1 +(0.003663 X 25) or 
1.091575 Cc. One Cc. of NO gas, therefore, weighing 0.00134256 
Gm. at 0° C. (32° F.) will weigh at 15° C. (59° F.) 0.0012726 
Gm. (0.00134256-5-1.054945=0.0012726), and at 25° C. (77° F.) 
0.0012319 Gm. (0.00134256-5-1.091575=0.0012319). 

Since 29.97 Gm. of NO gas represent 68.93 Gm. of NaN0 2 , as 



THE COMPOUNDS OF SODIUM. 451 

shown by the above equation, each Cc. NO gas at 15° C. (59° F.), 
weighing 0.0012726 Gm., must represent 0.002926 Gm. NaNO, ; 
for 29.97: 68.93:: 0.0012726: 0.002926; and each Gc. at 25° C. 
(77° F.), weighing 0.0012319 Gm., must represent 0.002833 Gm. 
NaN0 2 ; for 29.97 : 68.93 :: 0.0012319 : 0.002833. The Pharma- 
copoeia requires that 0.15 Gm. of sodium nitrite shall yield, at 15° 
C. (59° F.), not less than 50 Cc. of NO gas, and, at 25° C. (77° F.), 
not less than 51.7 Cc, to show at least 97.5 per cent, pure NaN0 2 ; 
97.6 per cent of 0.15 Gm. is 0.0146 -f , and 002926 X 50, or 
0.002833 X 51.7 = 0.0146 +. Slight solubility of the gas in the 
salt solution, and variations in barometric pressure, are overlooked 
in the official test, as they will not materially affect the result. 

Sodium Phosphate. Na 2 HP0 4 -j- 12H 2 0. Phosphoric acid 
being tribasic, is capable of yielding three classes of alkali salts^ 
known respectively as primary, secondary, and tertiary alkali phos- 
phate. The official salt, as shown by the chemical formula, is the 
secondary, or dibasic sodium phosphate, which usually shows a neu- 
tral or only faintly alkaline reaction toward litmus, the primary 
phosphate having an acid and the tertiary phosphate a decidedly 
alkaline reaction. Disodium orthophosphate, as the official salt is 
also known, is made by decomposing a solution of acid calcium phos- 
phate with sodium carbonate. The calcium salt is obtained by 
digesting calcined bone, or bone ash, with sulphuric acid, whereby 
the tricalcium phosphate (of which bone contains about 40 per cent.) 
is converted into acid calcium phosphate and calcium sulphate, the 
latter being precipitated ; thus, Ca 3 (P0 4 ) 2 -f 2H 2 S0 4 = CaH 4 (P0 4 ) 2 
-f- 2CaS0 4 ; the magma is then strained, and the resulting liquid, 
containing the acid calcium phosphate in solution, is mixed with 
sodium carbonate as long as precipitation occurs*, whereby secondary 
sodium phosphate is produced, and remains in solution, while cal- 
cium carbonate is precipitated and carbon dioxide expelled ; thus, 
CaH 4 (P0 4 ) 2 +2Na 2 CO a = 2Na 2 HP0 4 + CaC0 3 + C0 2 + H 2 0, The 
mixture is filtered and the filtrate concentrated and allowed to crys- 
tallize. 

The official sodium phosphate contains 60.3 per cent, of water of 
crystallization, a portion of which, about one-fourth, is lost by efflor- 
escence upon exposure to air ; moreover, carbon dioxide is gradually 
absorbed, the salt being converted into monosodium phosphate and 
acid sodium carbonate ; hence it must be preserved in well-stoppered 
bottles, in a cool place. At the temperature of boiling w 7 ater the 
salt can be made anhydrous ; but, when exposed in this condition, it 
again absorbs water, gradually forming a salt of the composition, 
Na 2 HP0 4 -f 7H 2 0, containing about 47 per cent, of water, which is 
permanent. Dried, granulated sodium phosphate occurs as an article 
of commerce, but should not be used when sodium phosphate is pre- 
scribed by physicians or in official formulas, as it contains, weight 



452 PHARMACEUTICAL CHEMISTRY. 

for weight, about one and one-half times the amount of actual 
Na 2 HP0 4 . 

The British Pharmacopoeia directs the preparation of effervescent 
sodium phosphate, which contains about 20 per cent, of the anhy- 
drous salt, together with sodium bicarbonate and tartaric and citric 
acids. Granulation is effected by placing the mixture in a dish 
heated to about 100° C. (212° F.), and stirring assiduously. 

Sodium Pyrophosphate. Na 4 P 2 7 + 10H 2 O. This salt is pre- 
pared by exposing crystallized sodium phosphate to gradually in- 
creased temperatures, when it first undergoes fusion at about 44° C. 
(111.2° F.) ; at 100° C. (212° F.) becomes anhydrous, and at a red 
heat, 300° C. (572° F.), is changed into a tetrabasic salt of pyro- 
phosphoric acid by the further elimination of water. Two mole- 
cules of the crystallized phosphate yield one molecule of the pyro- 
phosphate; thus, 2(Na,HP0 4 + 12H 2 0) = Na 4 P 2 7 + 25H 2 0. The 
dry residue is dissolved in water, aud the solution set aside to crys- 
tallize. 

The crystals of sodium pyrophosphate are difficult to reduce to 
fine powder, and are far less soluble in water than the ortho- 
phosphate. 

Sodium Salicylate. NaC 7 H 5 3 . The official salt may be 
conveniently obtained by mixing sodium bicarbonate 10 parts and 
salicylic acid 16.5 parts with distilled water 10 parts, in a glass or 
porcelain vessel, and, when effervescence has ceased, evaporating the 
solution, at a temperature not exceeding 60° C. (140° F.), to dry- 
ness. It is essential that the solution be slightly acid, hence, if 
necessary, a trifling addition of salicylic acid may be made, since 
alkali salicylates, in the presence of an excess of alkali, absorb 
oxygen from the air and become colored. Sodium bicarbonate and 
pure monocarbonate are better suited than sodium hydroxide for 
neutralizing the acid, since strong bases are apt to form different 
salts with salicylic acid, such as Na 2 C 7 H 4 3 , although the acid is 
monobasic ; these so-called secondary salicylates are less permanent 
and less soluble in water than the normal salts. 

All contact with iron must be carefully avoided in the preparation 
of this salt, owing to the delicate reaction of salicylic acid with that 
metal, and filtration through ordinary filter-paper is apt to color a 
solution of the salicylate, hence, pure cotton or glass wool is pre- 
ferable for straining. 

Sodium Sulphate. Na 2 S0 4 + 10H 2 O. This salt is daily ob- 
tained as a by-product in numerous chemical processes, such as the 
manufacture of hydrochloric and nitric acids and magnesium car- 
bonate, as well as the generation of carbon dioxide from sodium bi- 
carbonate with sulphuric acid, in the manufacture of carbonated 
waters. It is purified, if necessary, by recrystallization. 



THE COMPOUNDS OF SODIUM. 453 

The official salt, commonly known as Glauber's salt, contains 55.9 
per cent, of water of crystallization and effloresces rapidly upon ex- 
posure to air. 

For convenience in dispensing, the German Pharmacopoeia directs 
the preparation of dried sodium sulphate, by exposing the crystal- 
lized salt to a moderate heat until its weight has been reduced to one- 
half, as in the case of dried sodium carbonate. The dehydrated salt 
is in the form of a white powder and represents double the weight 
of the crystallized salt. 

Effervescent sodium sulphate is directed by the British Pharma- 
copoeia to be made from the anhydrous salt, in the same manner as 
stated under sodium phosphate. It contains about 25 per cent. 
Na 2 S0 4 . 

Sodium Sulphite. Na 2 S0 3 — 7H 2 0. Normal sodium sulphite 
is obtained by first preparing a solution of the acid sulphite, as 
already explained under sodium bisulphite, and then adding a weight 
of sodium carbonate equal to that first used, when a neutral salt will 
be formed ; thus, 2XaHSo 3 - Na 2 C0 3 = 2Na 2 SO a - C0 2 - H 2 0. 
The solution is then evaporated and allowed to crystallize. 

The official salt contains 50 per cent, of water of crystallization 
and is liable to be contaminated with the same impurities as the bisul- 
phite ; it effloresces upon exposure to air and, like the latter salt, is 
gradually converted into sulphate. The Pharmacopoeia requires that 
the salt shall contain at least 96 per cent, of crystallized Xa 2 S0 3 , 
which is determined by means of iodine solution, whereby all sul- 
phite present is converted into sulphate. According to the equation, 
Xa 2 So 3 .7H 2 - I 2 =Na 2 S0 4 - 2HI - 6H 2 0, each Cc. ill solution, 
containing 0.012653 Gm. of iodine, is capable of oxidizing 0.012579 
Gm. of the crystallized sulphite, hence 48 Cc. will be required for 
0.63 Gm. of the official salt. 

Sodium Suephocarbolate or Paraphexolsulphonate. 
NaS0 3 C 6 H 4 (OH) — 2H 2 0. When pure carbolic acid is mixed with 
an equal weight of sulphuric acid, a new compound is formed, to 
which the name sulpho-carbolic, or, more correctly, phenolsulphonic 
acid, has been given and which has the composition HS0 3 C 6 H 4 OH ; 
the acid is monobasic and is produced according to the equation, 
C 6 H 5 (OH) - H 2 S0 4 = HS0 3 C 6 H 4 OH - H 2 0. Two varieties of 
this acid are known, the ortho- and paraphenolsulphonic acids, the 
formation of which depends upon the temperature at which the re- 
action is allowed to go on ; in the cold, only the ortho variety is 
produced, while with moderate heat a mixture of the acids results, 
and at the temperature of boiling water only the para acid is ob- 
tained. Both varieties form clear solutious with water, but differ 
from each other in the character of their salts, both as regards solu- 
bility and form and constitution of the crystals. 

The Pharmacopoeia recognizes only the p«m-phenolsulphonate of 



454 PHARMACEUTICAL CHEMISTRY. 

sodium, which is prepared by heating a mixture of equal weights of 
carbolic and sulphuric acids, on a boiling water-bath for six hours, 
diluting the new compound with water aud neutralizing the hot 
liquid with an excess of barium carbonate. After filtration, the solu- 
tion of barium sulphocarbolate is decomposed by means of sodium 
carbonate, filtered, concentrated, and set aside to crystallize. The de- 
composition involves a very simple reaction ; thus, Ba (S0 3 C 6 H 4 (OH)) 2 
+ Na 2 C0 3 = 2NaS0 3 C 6 H 4 (OH) + BaC0 3 . Lead carbonate may 
be used in place of the barium carbonate to neutralize the newly 
formed phenolsulphonic acid, as lead sulphocarbolate is also soluble 
in water. 

The official salt contains about 15.5 per cent, of water of crystal- 
lization. The corresponding potassium sulphocarbolate is perfectly 
anhydrous, while the zinc salt crystallizes with 8 molecules or 25.94 
per cent, of water. 

Sodium Thiosulphate. Na 2 S 2 O s -j- 5H 2 0. This salt, wrongly 
called sodium hyposulphite, may be obtained in various ways, such 
as boiling a solution of sodium sulphite with sulphur (Na 2 S0 3 -j- S = 
Na.,S.,0 3 ), adding iodine to a solution of sodium sulphite and sul- 
phide" (Na 9 S0 3 + Na 2 S + I = Na 2 S 2 O a + 2NaI), boiling sulphur 
with solution of soda(6NaOH + S 12 = Na 2 S 2 O s + 2Na 2 S 5 + 3H 2 0), 
etc.; the process employed on a large scale, however, consists in de- 
composition of calcium thiosulphate in solution, by means of sodium 
carbonate or sulphate, insoluble calcium carbonate or sulphate being 
precipitated, while sodium thiosulphate remains in solution and is re- 
covered, after filtration, by crystallization ; the reaction may be thus 
indicated, CaS 2 3 -f Na 2 C0 3 — Na 2 S 2 3 -f CaC0 3 . Calcium thiosul- 
phate is obtained either from the residue left in the manufacture of 
sodium carbonate by the Leblanc process, known as alkali-waste, or 
from the gas-lime left in the purification of illuminating gas by dry 
lime. Both of these residues contain calcium sulphides which, upon 
exposure to the air, undergo oxidation and are converted into thio- 
sulphate. 

Unfortunately the Pharmacopoeia has retained the old name, 
sodium hyposulphite, as the official title for this salt, which is not in 
conformity with the chemical formula indicating its composition. 
True sodium hyposulphite has the formula NaHS0 2 , and may be 
prepared by treating a solution of sodium bisulphite with metallic 
zinc, whereby sodium hyposulphite and sulphite, together with zinc 
sulphite, are formed ; thus, 3NaHS0 3 -f Zn = NaHS0 2 + Na 2 S0 3 + 
ZnS0 3 4~ H 2 ; this salt is used by dyers and calico-printers. Hypo- 
sulphites can be distinguished from thiosulphates by heating them, 
when the former break up into thiosulphates and water, while the 
latter yield sulphates and sulphides. 

Sodium thiosulphate is employed to a limited extent in medicine, 
but its chief use in pharmacy is as a valuable chemical reagent in 
volumetric analysis. The official salt should contain at least 98.1 



THE COMPOUNDS OF SODIUM 455 

per cent, of pure crystallized Na 2 S 2 3 , which is determined by means 
of decinormal iodine solution iu the presence of starch. The reaction 
between iodine and sodium thiosulphate has already been explained 
in connection with the assay of chlorine water (page 409), and, since 
each Cc. of yiy iodine solution requires 0.02-1:764 Gm. Na 2 S 2 3 5H 2 0, 
it follows that at least 9.9 Cc. must be added to a solution of 0.25 
Gm. of the official salt before an excess will be indicated by the per- 
manent blue color of iodized starch, for 98.1 per cent, of 0.25 is 
0.02452 X and 0.02476 X 9.9 = 0.2451636. 

Solution of Soda. This preparation closely resembles the offi- 
cial solution of potassa, and can be made by either of the processes 
described on page 439, except that sodium salts are to be used in 
place of potassium salts. It has a spec. grav. of. about 1.059 at 15° 
C. (59° F.). 

Solution of soda should contain 5 per cent, by weight of absolute 
ISTaOH, equal to about 27 grains in each fluidounce, and, for reasons 
already stated in connection with solution of potassa, must be pre- 
served in green-glass bottles with tightly fitting stoppers coated with 
paraffin. 

The official solution of soda of the British Pharmacopoeia is slightly 
weaker than our own (4.1 per cent.), while that of the German Phar- 
macopoeia (liquor natrii caustici) contains 15 per cent., and that of 
the French Codex 23 per cent of caustic soda. 

Solution of Chlorinated Soda. The Pharmacopoeia directs 
that this solution shall be made by mixing strong solutions of 75 parts 
of chlorinated lime and 150 parts of sodium carbonate, whereby the 
lime salts are decomposed and precipitated as carbonate ; since chlori- 
nated lime consists of a mixture of calcium hypochlorite and chloride, 
the corresponding sodium salts will be present in the liquid after the 
above mixture has been filtered. The decomposition may be illus- 
trated by the following equation : Ca(ClO), -f CaCl., + 2STa 9 C0 3 = 
2]S T aC10 -f 2NaCl + 2CaC0 3 . The object of directing a hot solution 
of sodium carbonate to be used is to insure the formation of a dense 
precipitate of calcium carbonate, from which the liquid can be readily 
separated, otherwise much trouble will be experienced in filtration 
and washing. 

The preparation is more familiarly known as Labarraque's solution, 
and owes its value as a disinfectant to the available chlorine present, 
by which is meant, not the total amount of chlorine in combination, 
but the amount present as hypochlorite, which can be eliminated as 
free chlorine by the aid of an acid ; thus, NaCIO + HC1 = XaCl -f- 
HCIO and HCIO -|- HC1 == CI, + H 2 0. The solution should be pre- 
served in dark bottles provided with rubber stoppers, as light is 
detrimental to its stability, and cork stoppers are gradually destroyed 
by the liquid. The escape of carbon dioxide upon the addition of 
hydrochloric acid to the solution, is due to the decomposition of 



456 PHARMACEUTICAL CHEMISTRY. 

sodium carbonate, which is frequently present, owing to the variable 
composition of the chlorinated lime used in the manufacture. 

The official solution must contain at least 2.6 per cent, by weight 
of available chlorine, which is determined by liberating the chlorine 
with hydrochloric acid and allowing the same to act upon potassium 
iodide ; as explained under chlorine water (page 409), an equivalent 
quantity of iodine will be set free, the amount of which can be ascer- 
tained volumetrically with decinormal sodium thiosulphate solution, 
and from this the weight of chlorine liberated can be readily calcu- 
lated. Each Cc. —g- Na 2 S 2 3 + 5H 2 solution, corresponding to 0.01 2653 
Gm. of iodine, represents O.00d537 Gm. of chlorine, hence 50 Cc. 
will be required to decolorize the iodine liberated by 0.1742 Gm.. 2.6 
per cent, of 6.7 Gm. chlorine, in the official test. 

A preparation very similar to the foregoing is the solution of 
chlorinated potassa, better known as Javelle water, or eau de Javelle ; 
it is prepared by substituting an equivalent quantity of potassium 
carbonate for the sodium carbonate in the above process. 

Solution of Sodium Arsenate. Like Fowler's solution, this 
preparation may be more conveniently considered with the official 
compounds of arsenic. 

Solution of Sodium Silicate. This solution, under the name 
of liquid glass, or water-glass, is more extensively employed in the 
arts than by physicians. It is prepared by fusing together a mixture 
of finely powdered quartz and dried sodium carbonate, when sodium 
silicate is formed and carbon dioxide expelled ; the resulting product 
is treated with boiling water, filtered, and the solution concentrated. 
The official solution has a specific gravity of 1.30 to 1.40, and con- 
tains about 33 per cent, by weight of a mixture of sodium trisilicate 
and tetrasilicate (Na 2 S 3 7 and Na 2 S 4 9 ), which salts are less alkaline 
than the metasilicate, Na 2 Si0 3 , and, therefore, better adapted for 
surgical purposes. 

Besides the official salts of sodium, the following are of interest to 
pharmacists : 

Sodium Citrate. 2Na 3 C 6 H 5 O 7 ^-llII 2 0. Citric acid, being 
tribasic, is capable of forming three different salts with sodium, 
but the normal salt, or trisodium citrate, is the kind usually em- 
ployed. It is prepared by neutralizing a solution of citric acid with 
sodium carbonate or bicarbonate, concentrating the solution and al- 
lowing it to crystallize. To make 100 parts of the salt requires 58.8 
parts of citric acid and 121.5 parts of crystallized sodium carbonate 
or 71.6 parts of bicarbonate. The German Pharmacopoeia recog- 
nizes, under the name Potio Riveri, a freshly prepared effervescent 
solution of sodium citrate, made with 4 Gm. of citric acid, 7 Gms. of 
crystallized sodium carbonate, and 190 Cc. of water. 



THE COMPOUNDS OF SODIUM. 457 

Sodium Ethylate. C 2 H 5 ONa. This salt, also known as caus- 
tic alcohol, is obtained by direct action of metallic sodium on abso- 
lute alcohol, the metal being added in small pieces at a time, as long 
as the evolution of hydrogen continues, and the mixture kept cool by 
immersing the flask in water. The salt may be preserved in the 
form of crystals or powder in well-stoppered bottles. The British 
Pharmacopoeia directs a solution of sodium ethylate, to be made by 
dissolving 22 grains of metallic sodium in 1 fluidounce of absolute 
alcohol; it is a colorless, syrupy liquid, containing 19 percent, of the 
salt, and becoming brown by keeping. 

Sodium Santoninate. 2NaC 15 H 19 4 -{-7H 2 O. This salt, which 
was dropped from the Pharmacopoeia of 1890, can be made by dis- 
solving santonin in a hot solution of soda, filtering the solution and 
crystallizing in a cool place. It is soluble in 3 parts of water and 
12 parts of alcohol at ordinary temperature. 

Sodium Sulphovinate, or Ethylsulphate. NaC 2 H 5 S0 4 + 
H 2 0. When sulphuric acid is added gradually to an equal weight 
of alcohol, sulphovinic or ethylsulphuric acid is formed ; thus, 
C 2 H 5 OH+H 2 S0 4 =C 2 H 5 HS0 4 -fH 2 0; this can be neutralized by 
adding barium carbonate in excess, filtering the mixture and decom- 
posing the solution of barium sulphovinate by a solution of sodium 
carbonate or sulphate. After filtration the clear liquid is evaporated 
at a moderate heat and crystallized. The salt is very soluble in 
water aud also in alcohol and glycerin. 

Sodium Tartrate. Na 2 C 4 H 4 6 +2H 2 0. This salt may be 
prepared, like the citrate, by simple substitution of tartaric acid for 
citric acid. To make 100 parts requires 65.19 parts of tartaric acid 
and 125.73 parts of crystallized sodium carbonate, or 74.09 parts of 
bicarbonate. 

Sodium Valerianate. NaC 5 H 9 2 . This salt is recognized in 
the British Pharmacopoeia, and is made by neutralizing valerianic 
acid with caustic soda or sodium carbonate ; the solution is evapo- 
rated to dryness and the heat then continued until the salt fuses. If 
the valerianic acid is contaminated with anryl valerianate (apple oil), 
this will separate, and, floating as an oily liquor on the solution, can 
be removed. 



CHAPTEE XLII. 

THE COMPOUNDS OF LITHIUM. 

Five lithium salts are recognized in the Pharmacopoeia together 
with one effervescent preparation of a salt. A peculiarity of all 
lithium salts, by which they can be readily distinguished from other 
alkali salts, is their complete solubility in a mixture of equal volumes 
of alcohol and ether, after conversion into the chloride. 

The following is a list of the official lithium preparations : 

Official English Name. Official Latin Name. 

Lithium Benzoate, Lithii Benzoas. 

Lithium Bromide, . Lithii Bromidum. 

Lithium Carbonate, Lithii Carbonas. 

Lithium Citrate, Lithii Citras. 

Effervescent Lithium Citrate, Lithii Citras Effervescens. 

Lithium Benzoate. LiC 7 H 5 2 . This salt is most conveniently 
prepared from the carbonate, by suspending the same in hot water 
and adding benzoic acid as long as effervescence continues ; the fil- 
trate is evaporated on a water-bath to dryness, with constant stirring, 
or may be concentrated and set aside to crystallize. To make 100 
parts of the salt will require 29 parts of lithium carbonate and 95 
parts of benzoic acid, the reaction being as follows: 2HC 7 H 5 2 + 
Li 2 C0 3 =2LiC 7 Hp 2 +C0 2 +H 2 0. 

The salt is permanent in the air and very soluble in water, but 
less so in alcohol. The Pharmacopoeia requires practically absolute 
purity, which is determined as in the case of organic salts of the 
other alkalies. Two molecules, or 255.44 parts, of lithium benzoate 
yield, upon thorough ignition, 1 molecule, or 73.87 parts, of lithium 
carbonate; hence each Cc. T H 2 S0 4 , capable of neutralizing 0.036935 
Gm. of Li 2 C0 3 , must correspond to 0.12772 Gm. LiC 7 H 5 2 . 1 Gm. 
of lithium benzoate, after ignition, will therefore require 7.8 Cc. f 
H,S0 4 to indicate 99.6 per cent, of the pure salt; for 0.12772x7.8= 
0.996116. 

Lithium Bromide. LiBr. For the preparation of this salt 
diluted hydrobromic acid may be neutralized with lithium carbonate, 
or the latter salt may be agitated in a flask with a hot solution of 
ferrous bromide. The first method is probably the most desirable. 
Owing to the very deliquescent character of the salt it is not readily 
crystallized, and is preferably obtained in granular powder form by 
evaporating the solution to dryness on a water-bath. 

Lithium bromide contains about 92 per cent, of bromine, a larger 
proportion than any other salt. It is very soluble in water and 



THE COMPOUNDS OF LITHIUM. 459 

alcohol, and also soluble in ether, and mast be carefully preserved 
in well-stoppered bottles. 

The salt is likely to be contaminated with lithium chloride (due to 
chlorine in the bromine), and the Pharmacopoeia permits an admix- 
ture of 2 per cent, of this impurity, as shown by the official volumet- 
ric test. 0.3 Gm. of absolutely pure lithium bromide require only 
34.57 Cc. yV ^g^O s solution for complete precipitation, and 0.3 
Gm. pure lithium chloride require 70.79 Cc. ; according to the rule 
on page 434, each 0.3622 Cc. of the silver solution used in excess of 
34.57 Cc. in the official test indicates 1 per cent, of LiCl and 0.73 
Cc. (35.3-34.57=0.73) divided by 0.3622 is equal to 2. 

Lithium Carbonate. Li 2 C0 3 . The carbonate, the parent salt 
of the other lithium compounds, is obtained from the mineral lepido- 
lite, a mixture of silicates and fluorides of potassium, sodium, alum- 
inum, and lithium. By digestion with sulphuric acid impure lithium 
sulphate is obtained, which is freed from the other salts by crystalli- 
zation, treatment with milk of lime, etc. The final solution of alkali 
hydroxides is mixed with ammonium carbonate, whereby the lithium 
carbonate is precipitated ; or the mixed alkali hydroxides may be 
converted into chlorides, and the solution then treated with ammo- 
nium carbonate. For the purpose of purification lithium carbonate 
may be suspended in water and treated with carbon dioxide, when 
an acid carbonate, LiHC0 3 , will be formed and enter into solution, 
upon heating which pure lithium carbonate will be precipitated. 

Lithium carbonate is the least soluble of all alkali carbonates, 
and is, moreover, only a little more than half as soluble in boiling 
water as in cold water. It occurs in commerce as a light, odorless 
powder. 

The Pharmacopoeia requires that 0.5 Gm. of the salt suspended in 
water shall neutralize not less than 13 4 Cc. of normal acid, indi- 
cating at least 98.98 per cent, of pure Li 2 C0 3 ; since each Cc. J 
H 2 S0 4 requires 0.036935 Gm. of the pure carbonate ; 0.5 Gm. of the 
official salt must neutralize at least 13.4 Cc. ; for 98.98 per cent, of 
0.5 is 0.4949 and 13.4x0.036935=0.4949. 

Lithium Citrate. Li 3 C 6 H 5 7 . This salt can be prepared by 
adding lithium carbonate to a solution of citric acid until the latter 
is neutralized and evaporating the liquid to dryness, gradually rais- 
ing the temperature to 115° C. (239° F.). As shown by the equa- 
tion, 2H 3 C 6 H 5 7 .H 2 0+3Li 2 COs=2Li 3 C 6 H 5 7 + 3C0 2 +5H 2 0, 419 
parts of citric acid require 221.61 parts of lithium carbonate, the 
yield of citrate being equal to the weight of acid used. 

As shown by the chemical formula given for the official salt, the 
Pharmacopoeia recognizes only the anhydrous salt. If the above- 
mentioned solution be concentrated and allowed to crystallize, the 
resulting salt will have the formula Li 3 C 6 H 5 7 + 4H 2 0, and contain 
25.5 per cent, of water of crystallization, one-fourth of which cannot 



460 PHARMACEUTICAL CHEMISTRY. 

be eliminated at a temperature of a boiling water-bath ; this is the 
salt recognized in the British Pharmacopoeia. 

Both the anhydrous salt in powder form and the crystallized salt 
occur in commerce. 

Since 3 molecules of lithium carbonate invariably yield 2 mole- 
cules of the normal citrate, so inversely 2 molecules, or 419.14 parts, 
of lithium citrate will, upon ignition, yield 3 molecules, or 221.61 
parts, of the carbonate. In the official method of valuation of 
lithium citrate the alkaline residue left after ignition of 1 Gm. of 
the salt is required to neutralize at least 14.2 Cc. of normal acid, 
showing not less than 99.2 per cent, of anhydrous citrate. Each 
Cc. y H 2 S0 4 requiring 0.036935 Gm. Li 2 C0 3 for saturation corre- 
sponds to 0.0698566 Gm. Li 3 C 6 H 5 7 and 14.2 X 0.0698566=0.99196, 
which is equal to 99.2 per cent, of 1 Gm. 

Effervescent Lithium Citrate. This preparation does not 
contain lithium citrate in the finished product, but the salt is in- 
tended to be formed when the official powder is dissolved in water ; 
it is simply a mechanical mixture of the ingredients ordered by the 
Pharmacopoeia. The amount of citric acid ordered in the official 
formula is sufficient to decompose both the lithium and sodium car- 
bonates, leaving at the same time a slight excess of free acid, which 
amounts to about 7.7 Gm. in the total finished product. Each Gm. 
of the effervescent powder will yield, upon solution, 0.132 Gm. of 
anhydrous lithium citrate. 

The amount of sugar required in the preparation will depend, in 
part, upon the loss of weight in drying the citric acid as directed by 
the Pharmacopoeia. 

The powder must be preserved in a dry, cool place. 

Lithium Salicylate. LiC 7 H 5 3 . This salt may be prepared 
by heating a mixture of 44 parts of salicylic acid, 12 parts of lithium 
carbonate, and 100 parts of water until effervescence ceases; it is then 
filtered and the solution evaporated to dryness. As in the case of 
sodium salicylate, a slight excess of acid is necessary to avoid dis- 
coloration of the finished product, and contact with metal must be 
carefully avoided. 

Upon ignition, 2 molecules, or 287.36 parts, of lithium salicylate 
yield 1 molecule, or 73.87 parts, of the carbonate, and each Cc. of 
normal acid neutralized by the alkaline residue corresponds to 
0.14368 Gm. LiC 7 H 5 3 ; 13.8 Cc. f H 2 SO will therefore be required 
to indicate 99.13 per cent, if 2 Gm. of the salt be used, as directed 
in the official volumetric test. 



CHAPTER XLIII 



THE COMPOUNDS OF AMMONIUM. 



Although, thus far, all efforts to isolate the basylous radical of 
ammonium salts have failed, the existeuce of the hypothetical body 
XH 4 must be assumed, as, without it, it would be impossible to ex- 
plain the formation and composition of a large and important class 
of compounds in accordance with accepted modern views regarding 
the replacement of hydrogen in acids. The decomposition of sodium 
amalgam by means of ammonium chloride, resulting in the produc- 
tion of sodium chloride and a new spongy amalgam having a metallic 
lustre, points strongly to the metallic character of the radical called 
ammonium. The indirect source of all ammonium salts is the gaseous 
body ammonia, NH 3 , which may be looked upon as ammonium 
hydroxide minus water, NH 4 OH — H 2 = NH 3 • a characteristic 
feature of these salts is their complete volatilization upon application 
of heat. 

The Pharmacopoeia recognizes 7 salts of ammonium, 4 prepara- 
tions of the salts, and 3 solutions of the hydroxide, as follows : 



Official English Name. 
Ammonium Benzoate, 
Ammonium Bromide, 
Ammonium Carbonate, 
Ammonium Chloride, 
Ammonium Iodide, 
Ammonium Nitrate, 
Ammonium Valerianate, 
Ammonia Water, 
Stronger Ammonia Water, 
Liniment of Ammonia, 
Solution of Ammonium Acetate, 
Spirit of Ammonia, 
Aromatic Spirit of Ammonia, 
Troches of Ammonium Chloride, 



Official Latin Name. 
Ammonii Benzoas. 
Ammonii Bromidum. 
Ammonii Carbonas. 
Ammonii Chloridum. 
Ammonii Iodidum. 
Ammonii Nitras. 
Ammonii Valerianas. 
Aqua Ammonia;. 
Aqua Ammoniaj Fortior. 
Linimentum Ammoniac. 
Liquor Ammonii Acetatis. 
Spiritus Ammonias. 
Spiritus Ammoniae Aromaticus. 
Trochisci Ammonii Chloridi. 



Ammonium Benzoate. NH 4 C 7 H 5 2 . When benzoic acid is 
added to diluted ammonia water, the acid is neutralized and ammo- 
nium benzoate is formed, which, remaining in solution, may be 
obtained in colorless crystals, if the liquid be concentrated by aid of 
a moderate heat and set aside. As ammonium salts are readily de- 
composed by heat, the liquid should be kept alkaline by the occa- 
sional addition of ammonia water during evaporation. To prepare 
100 Gm. of the salt requires 87.75 Gm. of benzoic acid and 123 
Gm. of official ammonia water. 



Ammonium Bromide. NH 4 Br. Decidedly the best method of 
preparing this salt is by double decomposition between boiling hot 



462 PHARMACEUTICAL CHEMISTRY. 

concentrated solutions of ammonium sulphate and potassium bro- 
mide, when, upon cooling, the newly formed potassium sulphate is 
precipitated, while ammonium bromide remains in solution. To 
facilitate the removal of the potassium sulphate, alcohol is usually 
added to the cool liquid. The salt may be obtained in granular form 
by decanting the solution, coucentrating it, and evaporating to dry- 
ness, with constant stirring. 

Ammonium bromide may also be obtained quite pure by heating 
in a retort, on a sand-bath, an intimate mixture of potassium bro- 
mide and dried ammonium sulphate, and subliming the vapors of 
ammonium bromide in a suitable condenser. 

The Pharmacopoeia demands that not more than 1 per cent, of 
ammonium chloride shall be present in the official salt, by directing 
that 0.3 Gm. of it shall require not more than 30.9 Cc. of decinormal 
silver solution for precipitation. Since 0.3 Gm. of pure NH 4 Br 
require 30.7 Cc. /^ AgN0 3 solution and 0.3 Gm. of pure NH 4 C1 
require 56.2 Cc, the use of 30.9 Cc. really indicates a trifle less than 
1 per cent, of chloride (about 0.78 per cent.); but, for all practical 
purposes, it may be assumed to be 1 per cent. 

Ammonium Carbonate. NH 4 HC0 3 jSTH 4 NH 2 C0 2 . As shown 
by the chemical formula, the official salt is not the uormal carbonate, 
which would have the composition (NH 4 ) 2 C0 3 , but is a mixture of 
acid ammonium carbonate and ammonium carbamate. It is obtained 
on an extensive scale by heating ammonium chloride with an excess 
of chalk and condensing the resulting vapors in leaden chambers ; 
it is afterward resublimed. The decomposition is accompanied by 
the splitting off of ammonia and water ; hence the composition of 
the sublimate, as given in the Pharmacopoeia : 4NH 4 C1 + 2CaCO s 
= NH 4 HC0 3 NH 4 NH 2 C0 2 + 2CaCl 2 + NH 3 + H 2 0. 

The commercial ammonium carbonate is usually accompanied by 
empyreuma, to which its peculiar tarry odor is due, and for pharma- 
ceutical purposes only the purified article should be employed. 
Owing to the rapid deterioration of the salt under exposure to air, 
by the loss of both ammonia and carbon dioxide, it should be pre- 
served in tightly closed bottles, the best container being a wide- 
mouth fruit jar provided with a rubber ring and metal clasp for 
hermetically sealing the glass top. Only firm translucent pieces of 
ammonium carbonate should be used, as the opaque friable condition 
is indicative of chemical change causing the conversion of the salt 
into acid- or bicarbonate. 

When the official ammonium carbonate is dissolved in water it is 
converted into the so-called sesquicarbouate, a mixture of acid and 
normal carbonate; thus, NH 4 HC0 3 NH 4 NH 2 C0 2 +H 2 0=NH 4 HC0 3 
(NH 4 ) 2 C0 3 . The Pharmacopoeia requires that the official salt shall 
be absolutely pure, and, in the volumetric valuation with normal 
acid, 2.613 Gm. are required to neutralize 50 Cc. fH 2 S0 4 . The 
test can be explained as follows : Upon solution in water, as pre- 



THE COMPOUNDS OF AMMONIUM. 463 

viously stated, 156.77 parts of the official carbonate are changed to 
174.73 parts of the mixed acid and normal carbonates, which are 
decomposed by the sulphuric acid, forming ammonium sulphate with 
elimination of carbon dioxide and water, as shown by the following 
equation : 2(NH 4 HC0 3 + (NH 4 ) 2 C0 3 ) + 3H 2 S0 4 = 8(NH 4 ) 2 S0 4 + 
4C0 2 -f 4H 2 0. Since 349.46 parts of the mixed carbonates, repre- 
senting 313.54 parts of the official carbonate, can neutralize 293.46 
parts of absolute sulphuric acid, each Cc. yH 2 S0 4 containing 0.04891 
Gm. El>S0 4 , must correspond to 0.05226 Gm. of the official carbo- 
nate (for 293.46:313.54: : 0.04891 : 0.05226) and 2.613 Gm. of 
the official salt must neutralize 50 Cc. of normal acid, because 
2.613-f-0.05226 is equal to 50. 

Ammonium Chloride. NH 4 C1. Crude ammonium chloride is 
obtained by neutralizing the ammoniacal gas-liquors, condensed in 
the preparation and purification of illuminating gas from coal, with 
hydrochloric acid, evaporating the solution to dryness and sub- 
liming the salt in iron vessels. This product, being usually con- 
taminated with iron, is, for pharmaceutical purposes, purified by 
adding ammonia water to a hot solution of the salt, filtering to 
remove the precipitated ferric hydroxide, and evaporating the filtrate, 
with constant stirring so as to form a granular powder. 

Ammonium Iodide. NH 4 I. This salt is most conveniently 
prepared by double decomposition between potassium iodide and 
ammonium sulphate dissolved in a small quantity of boiling water ; 
when the mixture has cooled, alcohol is added to insure a more per- 
fect separation of the newly formed potassium sulphate, and the 
solution of ammonium iodide is filtered and evaporated to dryness, 
constantly stirring. The reaction is as follows : 2KI-|-(N'H 4 ) 2 S0 4 = 
2NH 4 I+K 2 S0 4 . 

Ammonium iodide must be preserved in tightly stoppered dark 
bottles, as it is very hygroscopic and is readily decomposed when 
exposed to air and light. As the Pharmacopoeia directs, the salt 
should never be dispensed after it has become deeply colored, but 
may be restored to its original condition by dissolving in as little 
water as possible, adding solution of ammonium sulphide until the 
color is discharged, then filtering to remove the precipitated sulphur 
and evaporating on a water-bath to dryness. The ammonium sul- 
phide added undergoes decomposition, uniting with the free iodine 
to form ammonium iodide, while sulphur is precipitated at the same 
time; thus, (NH 4 ) 2 S+I 2 =2NH 4 I+S. 

The official test for the presence of ammonium bromide and chlo- 
ride depends upon the very sparing solubility of silver iodide in 
water ; hence any turbidity or precipitate produced in the ammoniacal 
filtrate upon the addition of nitric acid must be due to the presence 
of silver bromide or chloride. If the ammonium iodide be absolutely 
pure, 17.3 Cc. y^- AgX0 3 solution will suffice for complete precipi- 



464 PHARMACEUTICAL CHEMISTRY. 

tation of the 0.25 Gm. NH 4 I directed in the test, but a larger quan- 
tity will be required if bromide or chloride be present. 

Ammonium Nitrate. NH 4 N0 3 . While this salt may be pre- 
pared by neutraliziug nitric acid with ammonia or ammonium car- 
bonate, it is more economically obtained, on a large scale, by mutual 
decomposition of ammonium sulphate and potassium nitrate ; the 
mixture of the two solutions is allowed to crystallize, when the less 
soluble potassium sulphate is first removed, after which crystals of 
ammonium nitrate are obtained and purified by recrystallization. 

The chief use of ammonium nitrate is in the preparation of nitrous 
oxide gas, N 2 0, as an anaesthetic in dental surgery, which is obtained 
by heating the crystallized salt to about 240° C. (464° F.), when 
the following decomposition takes place: NH 4 N0 3 =N 2 0-j-2H 2 0. 
The gas is thoroughly washed before administration. On account 
of the rapid solution of ammonium nitrate, it is often employed for 
freezing mixtures and artificial cold applications. 

Ammonium Valerianate. NH 4 C 5 H s 2 . This salt is pre- 
pared by neutralizing pure valerianic acid with ammonia, conduct- 
ing the gas directly into the acid so as to avoid the presence of water, 
and thereby obtaining better crystals. 

When perfectly neutral, ammonium valerianate has little disagree- 
able odor, but, as the salt is prone to decomposition, it is frequently 
accompanied by the characteristic odor of valerianic acid. The acid 
reaction sometimes observed in an aqueous solution of the salt is 
due to decomposition, which is also indicated by the pronounced 
odor of the free acid floating on the surface of the solution ; valeri- 
anic acid being monobasic, there can be no acid salt of the same ; 
hence any free acid present is due to loss of ammonia in the normal 
salt. 

The salt is rarely prescribed except in the form of the elixir of 
ammonium valerianate ; in the preparation of this elixir, it is cus- 
tomary to dissolve the salt in aromatic elixir, neutralizing any free 
acid present by means of ammonium carbonate. 

Ammonium valerianate must be carefully preserved in tightly 
stoppered vials. 

Ammonia Water. Under this name the Pharmacopoeia recog- 
nizes an aqueous solution of ammonia containing 10 per cent, by 
weight of the gas. It is prepared, on a large scale, by liberating 
ammonia from ammonium chloride or sulphate, by the aid of lime 
and heat, and conducting the gas into a series of receivers containing 
cold water, where it is rapidly absorbed ; the residue in the retort 
consists of either calcium chloride or sulphate, as the case may be ; 
thus, 2NH 4 C1 or (NH 4 ) 2 SO <4 +Ca(OH) 2 =2NH 3 +(CaCl 2 or CaS0 4 )-f 
2H 2 0. Ammonia water is also made by mixing the ammoniacal 
liquors of gas-works with milk of lime, heating and conducting the 



THE COMPOUNDS OF AMMONIUM. 465 

gas into water ; when made by this process the solution generally is 
less pure, being accompanied by empyreuma. 

Ammonia gas is very soluble in water, which, at 0° C. (32° F.), 
is capable of taking up 1050 volumes of the gas, and even at 15° C. 
(59° F.) retains 727 volumes in solution. The official ammonia 
water contains about 125 volumes of gas; that is, 1 Cc. holds 125 Cc. 
of ammonia gas in solution. 

Different grades of strength of ammonia water are found in com- 
merce, of which that designated as 16° corresponds to the official 
10 per cent, solution ; but it must be borne in mind that ammonia 
water is apt to deteriorate, by loss of ammonia gas, when kept in 
loosely stoppered vessels, such as carboys, especially if stored in a 
warm place. Ammonia water should be preserved in glass-stoppered 
bottles, although sound corks may be used if not allowed to come in 
contact with the liquid, by covering with prepared bladder, as small 
particles of cork allowed to fall into the liquid soon impart a yel- 
lowish color to the same. 

Ammonia water is commonly known as spirit of hartshorn ; in the 
British Pharmacopoeia it is recognized as solution of ammonia, and 
in the German Pharmacopoeia as solution of caustic ammonia. 

The strength of ammonia water is determined by titration with 
normal acid, each Cc. of which requires 0.01701 Gm. NH 3 for 
neutralization ; hence, if 3.4 Gm. of the water be used for the test, 
as officially directed, 20 Cc. fH 2 S0 4 should be necessary to produce 
a neutral solution, indicating the presence of 10 per cent, of ammonia 
gas; for 10 per cent, of 3.4 is 0.34, and 0.01701X20=0.342. 

Stronger Ammonia Water. This preparation differs from the 
preceding only in strength, containing 28 per cent, by weight of 
ammonia gas, and is prepared in a similar manner, except that the 
gas must be conducted into the cold water for a longer period of 
time, so that a greater amount may be absorbed. 

Stronger ammonia water is not used in medicine, but has been 
found a very convenient source of supply for small quantities of 
pure ammonia gas, by simply heating in a flask provided with a 
delivery-tube, and for this purpose has been officially recognized. It 
can also be employed for the manufacture of weaker solutions of 
ammonia, which can be prepared of any desired strength by diluting 
the stronger ammonia water with plain water in proper proportions by 
weight, as explained on page 66. On account of the readiness with 
which all solutions of ammonia part with the gas upon an elevation 
of temperature, care should be exercised in opening bottles contain- 
ing stronger water of ammonia, as serious accidents have been known 
to occur from the sudden expulsion of the liquid upon loosening the 
stopper, due to an accumulation of gas in the vessel. 

The commercial grade known as 26° ammonia water corresponds 
to the official stronger solution. It .should be purchased only in 
glass-stoppered bottles and preserved in a cool place. 

30 



466 PHARMACEUTICAL CHEMISTRY. 

The strength of the preparation is determined volumetrically, like 
that of the weaker solution, with normal acid. Since each Cc. 
\ H 2 S0 4 represents 0.01701 NH 3 gas, 28 Cc. will be required to 
neutralize 1.7 Gm. of the official 28 per cent, solution. 

Spirit of Ammonia. This is an alcoholic solution of ammonia, 
identical in strength with the official ammonia water — namely, 10 
per cent, by weight of gas. It is prepared by heating stronger 
ammonia water in a flask, at a temperature not exceeding 60° C. 
(140° F.), to avoid the transfer of aqueous vapor as far as possible, 
and conducting the gas into recently distilled alcohol. The object 
of the pharmacopoeial direction to use recently distilled alcohol kept 
in glass vessels is to avoid contamination with organic matters, 
always present more or less in alcohol as ordinarily preserved, and 
likely to cause coloration of the liquid upon addition of ammonia. 

Spirit of ammonia is intended to be used in place of water of 
ammonia whenever the addition of the latter would cause turbidity 
in resinous alcoholic solutions. 

Aromatic Spirit of Ammonia. A hydro-alcoholic solution of 
normal ammonium carbonate, pleasantly flavored with essential oils. 
It contains 70 per cent, by volume of alcohol, 1 per cent, of oil of 
lemon, and -^ per cent, each of those of lavender and nutmeg. 
When official ammonium carbonate is treated with alcohol a portion 
of the salt enters into solution, the carbamate being converted iuto 
carbonate, while the acid carbonate remains undissolved ; therefore 
the Pharmacopoeia directs, in the formula for this preparation, 
that ammonia water shall be added to the ammonium carbonate 
before the admixture of the alcoholic solution of essential oils. This 
causes a change of the official salt into normal carbonate, which is 
perfectly soluble in alcohol ; the change effected may be readily 
explained as follows: ]OT 4 HC0 3 NH 4 NH 2 CO 2 + NH 3 + H 2 = 
2(JN"H 4 ) 2 C0 3 . In order to insure the complete conversion of the 
ammonium salt, it has been found advantageous to allow the mixture 
of ammonium carbonate solution and ammonia water to stand for 
twelve or twenty-four hours before adding it to the alcoholic liquid, 
otherwise a saline precipitate may form. 

Since 157 parts of official ammonium carbonate will yield 192 
parts of the normal carbonate, the finished solution, if properly 
made, will contain 41.5 Gm. of the latter salt, or each Cc. will con- 
tain 0.0415 Gm. 

Solution of Ammonium Acetate. This preparation, also 
known as Spirit of Mindererus, is an aqueous solution of ammonium 
acetate, containing also small amounts of acetic and carbonic acids. 
It is preferably prepared fresh when wanted, as, when kept on hand 
for some time, it gradually loses carbon dioxide and absorbs ammonia 
from the air, finally acquiring an alkaline taste. Prepared according 






THE COMPOUNDS OF AMMONIUM. 467 

to the official formula, by dissolving 5 Gm. of ammonium carbonate 
(in firm pieces) in 100 Cc. of diluted acetic acid, the finished product 
will contain 0.073 -f- Gm. of ammonium acetate in each Cc. (about 
33 grains in each fluidouuce), together with a trifling amount of 
acetic acid ; to the latter, as well as to the carbon dioxide remain- 
ing in solution, the pleasant, refreshing taste of the preparation is due. 
100 Cc. of diluted acetic acid contain 6.048 Gm. of absolute acetic 
acid, of which, according to the equation, XH 4 HC0 3 XH 4 XH 9 CO., 
+ 3HC 2 H 3 2 = 3XH 4 C 2 H 3 2 + H 2 + 2C0 2 , 5.7274 Gm. are re- 
quired to saturate 5 Gm. of ammonium carbonate. 

The following unofficial salts of ammonium are sometimes used : 

Ammonium Bicarbonate. XH 4 HC0 3 . This salt has already 
been mentioned, in connection with the official carbonate, as the 
white pulverulent decomposition-product obtained when the official 
salt is exposed to air. It may be prepared either by treating official 
ammonium carbonate with twice its weight of water, when the car- 
bamate will be dissolved, leaving the acid- or bi-carbonate ; or the 
official salt may be kept for two w~eeks under a bell-glass over 
sulphuric acid and lime, when the carbamate will be decomposed 
into carbon dioxide and ammonia, which are absorbed by the acid 
and lime, leaving the bicarbonate as a friable mass. When perfectly 
dry, ammonium bicarbonate is free from ammoniacal odor ; it is 
soluble in 8 parts of water at 15° C. (59° F.), but is insoluble in 
alcohol. 

Ammonium Citrate. (XH 4 ) 3 C 6 H 5 7 . This may be prepared 
by neutralizing a solution of citric acid with ammonium carbonate 
or ammonia water and carefully evaporating the solution on a water- 
bath, adding a little ammonia water from time to time, as the salt is 
readily decomposed. 100 Gm. of citric acid require for neutraliza- 
tion either 74.83 Gm. of ammonium carbonate or 243.58 Gm. of 
ten per cent, ammonia water, yielding 124.86 Gm. of a salt of the 
above composition. 

Ammonium Phosphate. (XH 4 ) 2 HP0 4 . The British Pharma- 
copoeia directs this salt to be prepared by adding stronger ammonia 
water to diluted phosphoric acid until a slight alkaline reaction ensues, 
then evaporating the solution with occasional addition of ammonia 
water and setting the liquid aside so that crystals may form, which 
must be quickly dried on paper. 

Ammonium Salicylate. XH 4 C 7 H 5 3 . This may be prepared, 
like the corresponding potassium salt, by neutralizing salicylic acid 
with the alkali carbonate and carefully evaporating the solution to 
dryness. 100 parts of salicylic acid require 37.96 parts of the 



468 PHARMACEUTICAL PHARMACY. 

official ammonium salt, yielding 112.36 parts of ammonium sali- 
cylate. 

Ammonium Sulphate. (NH 4 ) 2 S0 4 . The crude salt is obtained 
by treating coal-gas liquor either with sulphuric acid or calcium sul- 
phate ; if the latter plan be followed, it is customary to percolate the 
gas-liquor through powdered gypsum, whereby ammonium sulphate is 
obtained in solution and calcium carbonate remains in the percolator. 
The solution is evaporated and crystallized, the crystals being purified 
by heatiug to about 240° C. (464° F.) to remove empyreumatic 
products, and final solution and recrystallization. 



CHAPTER XLIV. 

THE COMPOUNDS OF BAEIUM, CALCIUM, AND STEONTIUM. 

The compounds of these three metals used in pharmacy are com- 
paratively few in number, and may be conveniently grouped together. 
While there is but one official compound of barium, the Pharmaco- 
poeia recognizes ten compouuds of calcium and seven preparations of 
the same, but only three compounds of strontium. The following 
list embraces all that are officially recognized : 



Official English Name. 
Barium Dioxide, 

Calcium Bromide, 

Precipitated Calcium Carbonate, 

Prepared Chalk, 

Calcium Chloride, 

Calcium Hypophosphite, 

Precipitated Calcium Phosphate, 

Dried Calcium Sulphate, 

Lime, 

Lime Liniment, 

Chlorinated Lime, 

Sulphurated Lime, 

Solution of Lime, 

Syrup of Lime, 

Syrup of Calcium Lactophosphate, 

Chalk Mixture, 

Compound Chalk Powder, 

Troches of Chalk, 

Strontium Bromide 
Strontium Iodide, 
Strontium Lactate, 



Official Latin Name. 
Barii Dioxidum. 

Calcii Bromidum. 

Calcii Carbonas Prsecipitatus. 

Creta Prseparata. 

Calcii Chloridum. 

Calcii Hypophosphis. 

Calcii Phosphas Prsecipitatus. 

Calcii Sulphas Exsiccatus. 

Calx. 

Linimentum Calcis. 

Calx Chlorata. 

Calx Sulphurata. 

Liquor Calcis. 

Syrupus Calcis. 

Syrupus Calcii Lactophosphatis. 

Mistura Cretse. 

Pulvis Cretse Compositus. 

Trochisci Creta?. 

Strontii Bromidum. 
Strontii Iodidum. 
Strontii Lactas. 



The Compounds of Barium. 

Barium Dioxide. Ba0 2 . This compound is of interest because 
it is used in the preparation of solution of hydrogen dioxide intended 
for medicinal use. It is obtained by passing a current of air over 
barium oxide heated to about 450° C. (842° F.), when another atom 
of oxygen is taken up and the dioxide produced. The anhydrous 
commercial dioxide is recognized in the Pharmacopoeia, which must 
contain, however, not less than 80 per cent, of pure Ba0 2 . The 
valuation is made by determining, with potassium permanganate, 
the quantity of hydrogen dioxide produced from a given weight of 
barium dioxide. The equation, Ba0 2 + H 3 PO + = BaHPO, + H 2 2 , 
shows that one molecule, or 168.82 parts, of barium dioxide, when 



470 PHARMACEUTICAL PHARMACY. 

treated with phosphoric acid, yields one molecule, or 33.92 parts, of 
hydrogen dioxide, and since 1 Cc. ^ KMnO A solution requires, for 
complete decoloration, 0.001696 Gm. H 2 2 , as shown on page 407, 
it follows that each Cc. so decolorized will correspond to 0.008441 
Gm. Ba0 2 ; for 33.92 : 168.82 : : 0.001696 : 0.008441. 

In the official test, 2.11 Gm. barium dioxide are dissolved, with 
the aid of 7.5 Cc. of phosphoric acid, in sufficient ice-cold water to 
make 25 Cc. of solution, and to 5 Cc. of this solution, representing 
0.422 Gm. Ba0 2 , decinormal potassium permangauate solution is 
added from a burette until a permanent pink tint is produced. As 
each Cc. ^ KMnO, solution represents 0.008441 Gm. Ba0 2 , 40 Cc. 
will be necessary to show 80 per cent, of pure Ba0 2 in 0.422 Gm. ; 
for 80 per cent, of 0.422 is 0.3376 and 0.008441 X 40= 0.33764. 

Barium dioxide must be preserved in tightly closed vessels to 
prevent the absorption of moisture and carbon dioxide from the air. 



The Compounds of Calcium. 

Calcium Bromide. CaBr 2 . The simplest method for the prep- 
aration of this salt is the solution of calcium carbonate in hydro- 
bromic acid, an excess of the former being added, the mixture filtered 
when effervescence has ceased and the solution evaporated to dry- 
ness ; a white granular powder is thus obtained, which is very deli- 
quescent, and must be preserved in tightly stoppered bottles. 

The Pharmacopoeia demands practically absolute purity for this 
salt, by stating that 0.25 Gm. shall require 25 Cc. decinormal silver 
solution for complete precipitation. The equation, CaBr 2 + 2AgN0 3 
= 2AgBr -j- Ca(NO s ) 2 , shows that 199.43 parts of calcium bromide 
require 339.10 parts of silver nitrate, hence 25 Cc. T N ^ AgN0 3 solu- 
tion will precipitate 0.2492875 Gm. CaBr 9 , which is 99.7 per cent, 
of 0.25 Gm. 

Precipitated Calcium Carbonate. CaC0 3 . This salt, popu- 
larly known as precipitated chalk, is prepared by double decomposi- 
tion between calcium chloride and sodium carbonate; solutions of 
the two salts are mixed and heated, when calcium carbonate is thrown 
down as a dense precipitate while sodium chloride remains in solu- 
tion. The decomposition may be illustrated as follows : CaCl 2 -f- 
Na 2 C0 3 = CaCO s -f 2NaCl ; to remove the sodium chloride the 
mixture is poured on a strainer and the precipitate washed with 
boiling water until the washings no longer indicate the presence of 
chlorine. 

If calcium carbonate be precipitated in the cold, it is flocculent 
and voluminous, in which condition it is difficult to wash it entirely 
free from the sodium chloride, hence the use of heat is advantageous. 
The precipitate consists of a micro-crystalline powder, entirely free, 
however, from grittiness. 



THE COMPOUNDS OF CALCIUM. 471 

It is not adapted for internal use, but is employed in the prepara- 
tion of other calcium compounds. 

Prepared Chalk. CaCO s . The compound officially recognized 
under the name prepared chalk is native soft calcium carbonate, 
freed by elutriation from most impurities. Chalk occurs abundantly, 
as a soft earthy mineral, on the English coast, which, by repeated 
treatment with water, may be gradually freed from impurities and 
coarser particles. The process of elutriation has been fully explained 
on page 104. After collecting the suspended fine powder, the latter, 
while still moist, is formed into small nodular masses by means of a 
funnel and then dried. 

Chemically prepared chalk does not differ from the precipitated 
calcium carbonate, but, on account of its greater softness and adhe- 
siveness, it is better adapted for internal administration, and is the 
kind of chalk used in the official chalk mixture and troches. Al- 
though it is never so white, and is probably less pure than the pre- 
ceding article, the latter should never be used in its place. 

Calcium Chloride. CaCl 2 . This compound is extensively ob- 
tained, in a crude state, as a by-product in different chemical pro- 
cesses. It may be obtained pure either by dissolving pure calcium 
carbonate in pure hydrochloric acid or by dissolving ordinary chalk 
or marble in hydrochloric acid aud freeing the solution from iron 
and other impurities by treatment with chlorine and subsequently 
milk of lime ; the mixture is warmed and filtered, the filtrate being 
finally exactly neutralized with hydrochloric acid. 

If a concentrated solution of calcium chloride be set aside to crys- 
tallize, a salt of the composition CaCI 2 + 6H 2 0, containing nearly 
50 per cent, of water, will be obtained ; but if the solution be evapor- 
rated until a granular powder results, a very deliquescent white salt 
of the composition CaCl 2 -f- 2H 2 0, containing about 25 per cent, of 
water, is produced. The Pharmacopoeia recognizes only the anhy- 
drous salt, which requires for its preparation a temperature above 
200° C. (392° F.), perfect fusion not occurring much below a red 
heat. The official salt is very deliquescent and must be preserved in 
tightly stoppered bottles. 

Anhydrous calcium chloride is employed in pharmacy chiefly as a 
desiccating agent, while the crystallized salt is used as a reagent in 
analytical chemistry. 

Calcium Hypophosphite. Ca(PH 2 2 ) 2 . This salt, the parent 
salt of numerous other hypophosphites, is prepared by the direct 
action of phosphorus on calcium hydroxide in the form of milk of 
lime, phosphine, or hydrogen phosphide, being generated at the same 
time ; 3Ca(OH) 2 + 6H 2 + P 8 = 3Ca(PH 2 2 ) 2 + 2PH 3 . In order 
to avoid the formation of the very annoying and spontaneously in- 
flammable phosphine as far as possible, E. Scheffer, as far back as 



472 PHARMACEUTICAL PHARMACY. 

1858, advocated the use of partially oxidized phosphorus, prepared 
by treating it under water with atmospheric air, whereby the phos- 
phorus is changed to a spongy condition and combines more readily 
with lime, even at the ordinary temperature, but preferably if the 
mixture be heated to 55° C. (131° F.). When the reaction has ended, 
the mixture is filtered, the residue washed with water, and the united 
nitrates evaporated and either granulated or allowed to crystallize. 

Calcium hypophosphite is not hygroscopic, like the corresponding 
salts of potassium and sodium, and is very nearly as soluble in cold 
as in boiling water. The official salt should contain at least 99.68 
per cent, of pure Ca(PH 2 2 ) 2 , which is determined with decinormal 
potassium permanganate solutiou, as already explained under potas- 
sium hypophosphite (which see). In the official test, the addition of 
sulphuric acid to the solution of the calcium salt precipitates calcium 
sulphate, liberating at the same time hypophosphorous acid, which 
is then oxidized by the permanganate solution and converted into 
phosphoric acid. The reactions mav be indicated thus : 5Ca(PH 2 2 ) 2 
+ 5H 9 S0 4 = 5CaS0 4 + 10HPH,O 2 and 10HPH 2 O, + 8KMn0 1 + 
12H 2 8b 4 = 10H s PO 4 + 4K 2 S0 4 + - 8MdS0 4 + 12H 2 0, from which 
it may be seen that 1261.36 parts of potassium permanganate are 
required to oxidize the hypophosphorus acid obtainable from 848.35 
parts of calcium hypophosphite; one Cc. T ^ KMn0 4 solution corre- 
sponds, therefore, to 0.0021208 Gm. of pure Ca(PH 2 2 ) 2 , hence 0.1 
Gm. of the official salt, containing 0.009968 Gm. (99.68 per cent.) 
Ca(PH 2 2 ), will decolorize 47 Cc. ^ KMn0 4 solution. 

Precipitated Calcium Phosphate. Ca 3 (P0 4 ) 2 . Tricalcium 
phosphate may be obtained by digesting calcined bone with hydro- 
chloric acid, whereby acid calcium phosphate and calcium chloride 
are formed, both of which remain in solution, and, upon addition of 
ammonia, are converted into tricalcium phosphate and ammonium 
chloride, the former being precipitated and freed from the latter by 
repeated washing with water. The different steps in the process may 
be illustrated by the following equations : Ca 3 (P0 4 ) 2 + 4HC1 = 
CaH 4 (P0 4 ) 9 + 2CaCl 9 and CaH 4 (P0 4 ) 2 + 2CaCl 2 + 4JSTH 4 OH = 
Ca 3 (P0 4 ) 2 + 4NH 4 C1 + 4H 2 0. If the precipitation is effected in a 
cold solution, the resulting product will be more voluminous but less 
readily freed from accompanying impurities than if hot solutions are 
used. Precipitated calcium phosphate may also be obtained by add- 
ing a solution of calcium chloride and ammonia water to a solution of 
sodium phosphate, when the following reaction will occur: 3CaCl 2 + 
2NH 4 OH + 2Na 2 HP0 4 = Ca 3 (P0 4 ) 2 + 2NH 4 C1 + 4NaCl + 2H 2 0. 

The calcium phosphate of the German Pharmacopoeia differs from 
that of the United States and British Pharmacopoeias in being sec- 
ondary calcium phosphate, CaHP0 4 , obtained by decomposition of 
calcium chloride with sodium phosphate ; it is a crystalline powder 
and contains about 25 per cent, of water, having the formula 
CaHP0 4 + 2H 2 0. 



THE COMPOUNDS OF CALCIUM. 473 

Dried Calcium Sulphate. The terms dried gypsum and cal- 
cined plaster are also applied to this compound, which is obtained 
by carefully heating native crystalline calcium sulphate, or gypsum, 
CaS0 4 -f- 2H 2 0, until deprived of about three-fourths of its water. 
The heat must be carefully regulated and not allowed to exceed 
105° C. (221° F.), as above this temperature the last portions of 
water will be expelled and the compound become anhydrous. If 
heated to 200° C. (392° F.), gypsum loses its property of uniting 
with water and setting to a firm mass, thus becoming useless for sur- 
gical purposes. 

The official dried gypsum is a powder containing about 95 per 
cent, of calcium sulphate and 5 per cent, of water. It must be care- 
fully protected from moisture. 

Lime. CaO. Calcium oxide, better known as unslaked or caustic 
lime, is obtained by calcining calcium carbonate in suitable furnaces 
known as lime-kilns. Oyster-shells, limestone, marble, and other 
varieties of carbonate are used for the purpose, the final product 
varying in quality according to the source ; for pharmaceutical and 
chemical purposes, lime obtained by calcination of white marble is 
the most desirable, being less contaminated with impurities. 

Good lime occurs in hard but porous masses, which, upon addition 
of half their weight of water, become heated, and are converted into 
a soft white powder, known as slaked lime. The change is of a 
chemical nature, as is evidenced by the development of heat, resulting 
in the formation of calcium hydroxide, thus: CaO^-H 2 0=Ca(OH) 2 . 
Since lime, upon exposure to air, gradually absorbs moisture, and 
finally carbon dioxide, it must be preserved in well-closed vessels in 
a dry place. Lime thus changed by exposure is called air-slaked 
lime. 

Lime is used iu pharmacy as a dehydrating agent and for the 
preparation of the official solution and syrup of lime. When slaked 
and mixed with five or six times its weight of water it forms a mix- 
ture kuown as milk of lime. 

Chlorinated Lime. This compound, which owes its value en- 
tirely to the amount of available chlorine it contains, is prepared by 
exposing slaked lime to the action of chlorine gas. The views held 
by chemists regarding the nature of the compound formed differ, and 
the question has, at the present day, not yet been settled. Some 
contend that calcium hypochlorite, calcium chloride, and water are 
produced, according to the equation 2Ca(OH) 2 -j- Cl 4 = Ca(C10) 2 + 
CaCl 2 -f- 2H 2 0, while others regard the dry product as having the 
composition CaOCl 2 , or CaClOCl, which, upon the addition of water, 
breaks up into calcium hypochlorite and chloride. The preponder- 
ance of opinion, at present, is in favor of the latter view, partly be- 
cause the richest commercial samples of chlorinated lime or bleaching 
powder thus far produced do not contain the proportion of available 



474 PHARMACEUTICAL PHARMACY. 

chlorine (about 49 per cent.), which the compound Ca(C10) 2 + 
CaCl 2 + 2H 2 should yield. 

The term " chloride of lime," usually applied to this substance in 
commerce, is a misnomer, probably given to it long before the chem- 
ical nature of the manufacturing process was understood. 

Chlorinated lime always contaius some calcium hydroxide, to 
which its partial insolubility in water is due. It should always be 
kept in a cool, dry place, and protected from light, since the latter 
has a deleterious effect upon it, causing a loss of chlorine and oxygen 
with production of calcium chlorate and chloride. If of good quality, 
chlorinated lime is not deliquescent, the latter phenomenon indicating 
decomposition. 

Solutions of chlorinated lime should always be prepared, without 
heat, by triturating the powder in a mortar with successive portions 
of water and rapidly filtering through paper or cotton. 

The Pharmacopoeia requires that the official product shall contain 
at least 35 per cent, of available chlorine, which may be determined, 
as in the case of chlorinated soda, by treatment with hydrochloric 
acid and potassium iodide and subsequent titration of the liberated 
iodine with sodium thiosulphate. When hydrochloric acid is added to 
chlorinated lime, the following decomposition takes place : 2Ca(C10)Cl 
or (Ca(C10) 2 + CaCl 2 ) + 4HC1 = Cl 4 + 2CaCl 2 + 2H 2 0. The ac- 
tion of nascent chlorine on potassium iodide has been explained on 
page 409, and, from the amount of decinormal sodium thiosulphate 
solution used to decolorize the iodine solution, the weight of liberated 
chlorine can be calculated. Each Cc. -^0 Na 2 S 2 3 solution corre- 
sponds to 0.003537 Gm. of chlorine, therefore 35 Cc. will be neces- 
sary to indicate 0.1225 Gm. (35 per cent, of 0.35 Gm.), for 
0.003537 X 35 = 0.123795. 

Sulphurated Lime. The official process for this preparation 
consists in heating a mixture of 70 parts of dried calcium sulphate, 
10 parts of charcoal, and 1 part of starch, in a loosely covered 
crucible, to bright redness, until a uniform gray color results. The 
reaction consists in the reduction of calcium sulphate to sulphide and 
the formation of carbon monoxide and dioxide, which escape, thus : 
CaS0 4 + C 3 = CaS + 2CO + C0 2 . The starch simply aids in the 
reduction, which, however, is not complete, as the finished product 
contains unchanged calcium sulphate and carbon in varying pro- 
portions. 

Sulphurated lime, being liable to decomposition when exposed to 
air, must be carefully preserved in air-tight vessels. The official 
article is required to contain at least 60 per cent, of calcium mono- 
sulphide, upon which the virtues of the preparation depend ; the 
determination being made by adding 1 Gm. of sulphurated lime to 
a boiling solution of 2.08 Gm. of crystallized cupric sulphate, when 
the copper should be completely precipitated as sulphide. The equa- 
tion, CuS0 4 .5H 2 + CaS = CuS + CaSoi + 5H 2 Q, shows that 



THE CO MP VXDS OF CALCIUM. 475 

248.8 parts of crystallized cupric sulphate require 71.89 parts of cal- 
cium inonosulphide, hence 2.08 Gm. will require 0.601 Gm., which 
is practically 60 per cent, of 1 Gm. 

Solution of Lime. This liquid, more familiarly known as lime- 
water, is intended to be a saturated solution of calcium hydroxide. 
The official directions for its preparation are simple and easily fol- 
lowed, the object of rejecting the first solution obtained after half an 
hour's maceration of the slaked lime with water being to get rid of 
the more soluble impurities, after which the purified lime is kept in 
contact with water as long as it continues to furnish a saturated solu- 
tion. It must not be supposed, however, that lime will furnish uu- 
limited quantities of lime-water, and the supply should be tested 
from time to time, either volumetrically, as directed by the Phar- 
macopoeia, or empirically, by breathing into a small quantity of it 
through a glass tube or boiling a little of it in a test-tube — in either 
case a turbid liquid should result, due to the separation of calcium 
carbonate in the first place, or calcium hydroxide in the second. 

Lime-water is a very important article in pharmacy, and should 
receive careful attention, as it is chiefly used as an antacid for deli- 
cate infants. Pure lime, free from alum, should be used, and either 
distilled water, or that which has been boiled and cooled. The sup- 
ply of lime-water should be kept in tightly corked bottles, in a 
cool place, as carbon dioxide is readily absorbed and heat is un- 
favorable to solution of the lime. Lime-water is best decanted 
from the sediment — or, if filtered, this must be done under cover 
— the sediment should then be again well distributed in the liquid, 
by agitation, after the desired supply of solution has been with- 
drawn. 

"While a saturated aqueous solution of lime, at 15° C. (59° F.), 
contains about 1.70 or 1.75 Gm. of calcium hydroxide in every liter, 
the official requirement of 1.40 or 1.48 Gm. per liter more nearly 
represents the average strength of good lime-water. According to 
the equation, (H 2 C 2 4 - 2H 2 0) -f Ca(OH) 2 = CaC 2 4 -f 4H 2 0, each 
Cc. of decinormal oxalic acid solution, containing 0.006285 Gm. of 
oxalic acid, will neutralize 0.003691 Gm. of calcium hydroxide, hence, 
if 50 Cc. of lime-water require 20 Cc. ^L H 2 C 2 4 solution, as stated 
in the official test, about 0.07382 Gm. Ca(OH) 2 is present, which is 
equal to about 0.140-0.1476 per cent. 

Syrup of Lime. This preparation contains a much larger pro- 
portion of lime in solution than lime-water, owing to the presence of 
sugar, and is, therefore, preferred in some cases. It has also been 
recommended as an antidote in cases of poisoning by carbolic acid, 
and is said to have been used with good results. As already stated 
on page 224, syrup of lime, when freshly prepared, contains about 3.2 
Gm. of lime, CaO, in every 100 Cc. (about 16 grains in 1 fluidounce); 
as it absorbs carbon dioxide rapidly from the air, it must be carefully 



476 PHARMACEUTICAL CHEMISTRY. 

preserved, and, when nitration is necessary, as in its preparation, 
covered funnels only should be used. 

The saccharated solution of lime of the British Pharmacopoeia is 
a similar preparation, but contains only about one-half as much cal- 
cium oxide in solution. 

Syrup of Calcium Lactophosphate. This syrup has already 
been fully considered on page 224. 

The Compounds of Strontium. 

Strontium Bromide. SrBr 2 + 6H 2 0. This salt may be pre- 
pared by neutralizing diluted hydrobromic acid with pure strontium 
carbonate added in excess, filtering the mixture, and evaporating the 
solution until crystals begin to form. Upon cooling, the salt sepa- 
rates in crystals which should be dried at a moderate heat. 

Since pure strontium carbonate is difficult to obtain, the use of 
pure strontium hydroxide has been suggested instead, as the latter 
may be prepared readily from the nitrate by converting it into oxide 
by calcination and then slaking this with water, removing any 
barium and calcium present by further appropriate treatment with 
water. 

The official salt contains about 30.4 per cent, of water of crystal- 
lization, and deliquesces rapidly upon exposure to air. It can be 
rendered anhydrous by heating to 120° C. (248° F.), and, in that 
condition, should contain not less than 98 per cent, of absolute SrBr 2 , 
as determined by meaus of decinormal silver nitrate solution, the 
reaction being identical with that explained under Potassium Bro- 
mide (see page 434). 0.3 Gm. of anhydrous absolute strontium 
bromide require 24.32 Cc. ^ AgN0 3 solution for complete precipi- 
tation, w T hile 0.3 Gm. of absolute strontium chloride require 37.21 
Cc. ; hence, each 0.1289 Cc. required in excess of 24.32 Cc. will 
indicate 1 per cent, of chloride present. In the official test, 24.6 
Cc. ^ AgN0 3 solution are allowed, which will indicate practically 
2 per cent, of chloride ; for 24.6-24.32 = 0.28 and 0.28 -r- 0.1289 = 
2.17. 

Strontium Iodide. Srl 2 + 6H 2 0. Like strontium bromide, 
this salt may be prepared either from pure strontium carbonate or 
hydroxide by solution in the respective acid, but, since solution of 
hydriodic acid is rather unstable, it should be freshly prepared for 
the purpose. The process is identical with that for the preced- 
ing salt. 

Strontium iodide is also deliquescent but contains less water of 
crystallization (24.05 per cent.) than the bromide. By exposure to 
air and light it is colored yellow, and must, therefore, be preserved 
in dark, amber-colored bottles. 

The Pharmacopoeia requires that at least 98 per cent, pure stron- 



THE C03IP0UXDS OF STB0XTIU3I. 477 

tiuni iodide shall be contained in the anhydrous salt. Since not 
more than 18 Cc. of decinormal silver nitrate solution shall be re- 
quired for precipitation of 0.3 Gm. of the anhydrous salt, 0.73 Cc. is 
allowed for possible admixture of bromide and chloride, because 
0.294 Gm. (98 per cent, of 0.3) of absolute strontium iodide require 
only 17.27 Cc. of the silver solution. 

Strontium Lactate. Sr(C 3 H 5 3 ) 2 -f 3H 2 0. Strontium lactate 
is made by neutralizing moderately dilute lactic acid with strontium 
carbonate or hydroxide and evaporating the resulting solution to 
dryness with a moderate heat. The salt is not deliquescent. 

The nature of the compound, as regards the acid radical present, 
is determined by treating a 5 per cent, solution of the salt with potas- 
sium permanganate in the presence of sulphuric acid, as directed in 
the Pharmacopoeia. The decoloration of the red permanganate solu- 
tion, together with effervescence of the mixture and development of 
an aldehyde odor, is due to oxidation of the lactic acid, which is first 
liberated from the salt by sulphuric acid. Under the influence of 
oxidizing agents, lactic acid breaks up into acetic aldehyde, C 2 H 4 0, 
and formic acid, HHC0 2 , the latter being still further oxidized to 
carbon dioxide and water. 

The official salt, having been rendered anhydrous, should contain 
not less than 98.6 per cent, of pure strontium lactate, which is deter- 
mined by converting it into carbonate by means of ignition and then 
titrating the carbonate with normal acid. 1.33 Gm. of anhydrous 
strontium lactate will yield, upon ignition, 0.73886 Gm. of strontium 
carbonate, as shown by the equation, Sr(C 3 H 5 0,) 2 -j- 12 = SrC0 3 -f- 
5CCX + 5H 2 0, and, as each Cc. * H 2 S0 4 requires 0.073886 Gm. 
SrC0 3 for neutralization, it will correspond to 0.13244 Gm. anhy- 
drous strontium lactate; hence, 9.9 Cc. will be required to show 98.6 
per cent, of 1.83 Gm., for 0.13244 X 9.9 = 1.311 + and 98.6 per 
cent, of 1.33 is 1.311 -f. 



CHAPTEE XLV. 

THE COMPOUNDS OF MAGNESIUM. 

Although the official magnesium salts are but few in number 
they are extensively employed both by physicians and in domestic 
practice. The Pharmacopoeia recognizes six preparations of magne- 
sium, of which one is a liquid. The following comprise the list : 

Official English Name. Official Latin Name. 

Magnesia, Magnesia. 

Heavy Magnesia, Magnesia Ponderosa. 

Magnesium Carbonate, Magnesii Carbonas 

Effervescent Magnesium Citrate, Magnesii Citras Effervescens. 

Magnesium Sulphate, Magnesii Sulphas 

Solution of Magnesium Citrate, Liquor Magnesii Citratis. 

Magnesia. MgO. The name, calcined magnesia, by which this 
compound is commonly known, indicates the manner of its prepara- 
tion. Magnesium carbonate is pressed somewhat firmly into a crucible 
and then heated to dull redness, whereby carbon dioxide and water 
are expelled, leaving about 42 per cent, of residue consisting of mag- 
nesium oxide. The process is known to be completed when a small 
quantity of the residue, suspended in water, no longer effervesces 
upon addition of an acid. The heat is not allowed to rise to full red- 
ness unless the powder can be kept constantly stirred, otherwise the 
magnesia is very apt to become granular. The following equation 
illustrates the change taking place : (4MgC0 3 + Mg(OH) 2 + 5H 2 0)= 
5MgO+4CO ? +6H 2 0. 

Two varieties, a light and a dense calcined magnesia, occur in com- 
merce ; the latter is recognized in the Pharmacopoeia as heavy magnesia, 
or magnesia ponderosa. The two varieties are obtained in the same 
manner, but from light and heavy magnesium carbonate, respectively. 
Light magnesia is the kind generally used, and should invariably be 
employed when magnesia is to be dispensed in aqueous suspension ; 
small quantities of water cannot be mixed with it without. rendering 
it harsh and gritty, and, if 1 part of magnesia be added to 15 parts 
of water, the mixture will soon set to a gelatinous mass, hence care 
must be observed that sufficient water be used to overcome this ten- 
dency, and never should the water be added to the magnesia, but 
always the magnesia to the water. This peculiar behavior with 
water is due to the formation of gelatinous magnesium hydroxide, 
Mg(OH) 2 , and is characteristic of the light magnesia, heavy magnesia 
not readily uniting with water. 

Light and heavy magnesia do not differ from each other chemi- 



THE COMPOUNDS OF MAGNESIUM. 479 

cally ; the latter is a smoother and denser powder, preferred for use in 
powder mixtures on account of its smaller bulk. 

Since magnesia absorbs moisture aud carbon dioxide readily from 
the air, it must be preserved in tightly closed tin or glass vessels. 
The Pharmacopoeia demands that ouly slight traces of carbonate shall 
be present, and not more than 5 per cent, of moisture. 

Magnesium Carbonate. 4MgC0 3 + Mg(OH) 2 + 5H 2 0. As 
shown by the chemical formula, the official magnesium carbonate is 
not a pure normal carbonate, but is composed of magnesium car- 
bonate aud hydroxide united with water. It is prepared by mutual 
decomposition between solutions of magnesium sulphate or chloride, 
and of sodium carbonate; the composition of the resulting precipi- 
tate depends upon the concentration of the solutions employed and 
the temperature at which the decomposition is effected, and the pre- 
cipitate dried. Pure normal magnesium carbonate is never obtained 
when a solution of the sulphate or chloride is mixed with an alkali 
carbonate, but always a basic carbonate, the proportion of normal 
carbonate present in the precipitate being greatest, when dilute so- 
lutions are used at ordinary temperature. 

If solutions of magnesium sulphate and sodium carbonate be 
mixed in the cold, no carbon dioxide is eliminated, a voluminous 
precipitate of basic magnesium carbonate being thrown down, while 
an acid magnesium carbonate, MgH 2 (C0 3 ) 2 , remains in solution ; 
but, if the solutions be mixed warm or hot, carbon dioxide is evolved. 
The reaction producing the official magnesium carbonate is prob- 
ablv as follows : 5(MgS0 4 + 7H 9 0) + 5(Na,C0 3 -f 10H.,O) = 
(4MgCO a + Mg(OH) 2 + 5H 2 0) + 5Na 2 SO, + C0 2 + 79H 2 0, dilute 
solutions being used and mixed at a temperature uot above 55° C. 
(131° F.); the precipitate is washed to remove sodium chloride, and 
dried without heat. 

Both light and heavy magnesium carbonate occur in commerce, 
being manufactured extensively in this country and in England. 
The U. S. Pharmacopoeia recognizes only the light variety, as indi- 
cated by the official description ; this is also known as magnesia alba. 
The British Pharmacopoeia recognizes both the light and heavy mag- 
nesium carbonate and gives working formulas for their preparation, 
which differ from each other only in the concentration of the solu- 
tions used and in the length of time the mixture is boiled; the 
official English magnesium carbonate has the composition, SMgGHI^- 
Mg(OH) 2 + 4H 2 0. 

Considerable magnesium carbonate is also made in England from 
dolomite, a native magnesium limestone, by ignitiou and treatment 
with water and carbon dioxide under pressure ; acid magnesium car- 
bonate is formed and readily dissolved, and the solution,- separated 
from the calcium carbonate, is treated with steam, whereby the basic 
carbonate is precipitated. » 



480 PHARMACEUTICAL CHEMISTRY. 

Effervescent Magnesium Citrate. This preparation con- 
sists of acid magnesium citrate, MgHC 6 H 5 7 , mixed with sodium 
bicarbonate, citric acid, and sugar. It has already been fully con- 
sidered, in connection with other granular effervescent salts, on 
page 368. 

Magnesium Sulphate. MgS0 4 -f 7H 2 0. This salt, better 
known as Epsom Salt (a name given to it in connection with its first 
production at Epsom, England, in 1695), may be made from native 
magnesium carbonate, magnesite, by treatment with diluted sulphuric 
acid, but is obtained, on a more extensive scale, from kieserite, a 
native magnesium sulphate, found near Stassfurt, in Germany. The 
mineral is first heated by itself and then treated with boiling water, 
whereby the magnesium sulphate is brought into solution, being sub- 
sequently purified by recrystallization. 

Magnesium sulphate contains 51.13 per cent, of water of crystal- 
lization, and, exposed to dry air, slowly effloresces. The small acic- 
ular or rhombo-prismatic crystals, in which it occurs in commerce, 
are produced by agitation of the crystallizing solution, whereby the 
formation of large crystals is prevented. 

Several natural purgative waters, known as bitter waters, owe their 
cathartic properties to the magnesium sulphate which they contain. 

The German Pharmacopoeia directs the preparation of dried mag- 
nesium sulphate, for dispensing purposes, in powder form. It is 
made by gradually heating crystallized magnesium sulphate, on a 
water bath, until about two-thirds of the w T ater has been expelled ; 
the resulting white powder must be preserved in tightly corked bottles. 

Effervescent magnesium sulphate, recognized in the British Phar- 
macopoeia, has already been considered in connection with efferves- 
cent magnesium citrate, on page 368. 

Solution of Magnesium Citrate. This popular preparation 
is directed to be made by first forming a solution of citric acid 
30 Gm., magnesium carbonate 15 Gm., and water 120 Cc, and adding 
to it water 180 Cc, syrup of citric acid 60 Cc, and potassium bicar- 
bonate 2.5 Gm., whereby the liquid is rendered effervescent and more 
agreeable in taste. The solution has been the source of frequent 
annoyance on account of the disposition to deposit if kept on hand 
for a little while ; this difficulty, however, is, as a rule, due to a faulty 
formula and can be obviated. Magnesium carbonate and citric acid 
are capable of forming both normal and acid citrate, dependent upon 
the proportions of acid and base employed. The normal citrate, 
having the composition, Mg 3 (C 6 H 5 7 ) 2 , is but slightly soluble in 
water and crystallizes from its solutions with 14 molecules, or about 
36 per cent., of water ; it is the cause of the crystalline precipitate 
often found in solution of magnesium citrate, and is formed when- 
ever 1 part of magnesium carbonate and 1.44 parts of citric acid are 
brought together. Acid magnesium citrate, MgHC 6 H 5 7 , requires 



THE COMPOUNDS OF MAGNESIUM. 481 

2.16 parts of citric acid for each part of magnesium carbonate used; 
it is very soluble in water, but is objected to by many on account of 
its very acid taste. 

By following the official formula, a mixture of normal and acid 
magnesium citrate is produced, as insufficient citric acid is used to 
form the latter salt alone. Since 2.5 Gm. of potassium bicarbonate 
require about 1.75 Gm. of citric acid for complete decomposition, 
and only 0.6 Gm. are furnished by the 60 Cc. of syrup of citric acid 
ordered, there will be still less acid magnesium citrate in the finished 
product and the tendency to deposit the normal salt will be increased. 
The first edition of the 1890 Pharmacopoeia directed 120 Cc. of syrup 
of citric acid, but this was changed afterward, as the solution w r as 
found too sweet, containing about 100 Gm. of sugar in every bottle. 
For extemporaneous preparation of solution of magnesium citrate, 
the pharmacopoeial formula answers admirably and the citric acid 
may even be reduced to 25 Gm., with advantage as regards the taste ; 
but, if the solution is to be kept in bottles, for possibly a week or 
two or even longer, a more acid solution should be prepared, using 
33.58 Gm. of citric acid in place of 30 Gm., as officially directed. 

Another source of trouble is the use of plain water, which some- 
times causes fungi to form and renders the solution unsightly; this 
can be obviated by boiling and filtering all the water to be used. 
Sound soft corks only should be used for closing the bottles, and, hav- 
ing been first swelled in water for an hour, they should be driven 
firmly into the neck of the bottle aud then secured w T ith twine or 
wire, as retention in the solution of all the carbon dioxide, from the 
potassium bicarbonate, adds materially to the refreshing taste. The 
bottles should be kept in a cool place, resting on their sides. 



31 



CHAPTER XLVI. 

THE COMPOUNDS OF ALUMINUM AND CERIUM. 

There are but four compouuds of aluminum and one of cerium 
recognized in the Pharmacopoeia, as shown by the following list : 

Official English Name. Official Latin Name. 

Alum, Alum en. 

Dried Alum, Alumen Exsiccatum. 

Aluminum Hydrate, Alumini Hydras. 

Aluminum Sulphate, Alumini Sulphas. 

Cerium Oxalate, Cerii Oxalas. 

The Compounds of Aluminum. 

Alum. Al 2 K 2 (S0 4 ) 4 -{-24H 2 0. In pharmacy and medicine the 
term alum is applied to but one compound, although chemists recog- 
nize under the general name of alum several definite salts, the char- 
acteristics of which are, that they are double sulphates of a univalent 
and trivalent element, are isomorphous, crystallizing in the regular 
system of the cube and octahedron, and contain 24 molecules of 
water of crystallization. The univalent elements present may be 
either potassium, sodium, ammonium, caesium, rubidium, or silver, 
while the trivalent element need not necessarily be aluminum, its 
place being sometimes taken by iron, chromium, or manganese. The 
official alum is designated more specifically as potassium alum; 
besides this, the following are also known : ammonium alum, 
A1 2 (NH 4 ) 2 (S0 4 ) 4 +24H 9 0; chrome alum, Cr 2 K 2 (S0 4 ) 4 +24H 2 0; iron 
alum, Fe 2 (NH 4 ) 2 (S0 4 ) 4 +24H 2 0, etc., etc. 

Crude alum occurs in Nature in the form of alunite or alumstone, 
a mixture of aluminum hydroxide and aluminum and potassium sul- 
phates ; from this as well as alum-shale and the minerals cryolite and 
bauxite official alum is obtained. Calcination and lixiviation, as 
well as treatment with sulphuric acid and addition of potassium sul- 
phate or chloride, are brought into requisition in the different pro- 
cesses, crystallization being finally employed for the purpose of 
purification. Owing to the presence of iron in the minerals from 
which alum is made, it is often found in the latter, but should not 
exceed traces, as determined by the official test with potassium ferro- 
cyanide. 

Potassium alum is not quite so soluble as ammonium alum, which 
latter was formerly recognized in the Pharmacopoeia, and is still 



THE COMPOUNDS OF ALUMINUM AND CERIUM. 483 

more extensively handled in commerce than the official article, partly 
on account of its lower price. The British Pharmacopoeia recognizes 
both varieties. Ammonium alum may be readily distinguished from 
the official alum by the evolution of an ammoniacal odor upon tritu- 
ration with potassium or sodium hydroxide or carbonate; moreover, 
upon heating, ammonium alum leaves a final residue of pure alumina, 
while the residue from official alum contains potassium sulphate be- 
sides. 

Dried Alum. A1 2 K 2 (S0 4 ) 4 . Crystallized potassium alum con- 
tains 45.52 per cent, of water of crystallization, which may be en- 
tirely expelled at a temperature of 200° C. (392° F.). In "the offi- 
cial process for preparing dried or burnt alum, the crystals are first 
fused in a shallow capsule, the heat being then increased and con- 
tinued until 10 parts have been reduced in weight to 5.5 parts and 
a white porous mass remains, which is preserved in powder form in 
tightly stoppered bottles. A temperature exceeding 200° C. (392° 
F.) must be avoided to prevent decomposition and change of the 
aluminum sulphate to alumina, with loss of sulphuric acid. 

Dried alum, although completely but slowly soluble in water, re- 
quires about three or four times as much water for solution as the 
crystallized alum. 

Aluminum Hydrate or Hydroxide. Al 2 (OH) 6 or Al(OH) 3 . 
The Pharmacopoeia directs this compound to be prepared by gradu- 
ally pouring a hot solution of alum into a hot solution of an equal 
weight of sodium carbonate, repeatedly washing the resulting 
precipitate with hot water, and finally dLying the residue at a tem- 
perature not above 40° C. (104° F.). The decomposition is accom- 
panied by the evolution of carbon dioxide, and may be illustrated 
as follows : SXa 2 CO s - A1 2 K 2 (S0 4 ) 4 + 3H 2 = Al^OH^-f-KjSC^-f- 
3Xa 2 S0 4 + 3C0 2 ; this peculiar reaction is characteristic of certain 
metals, aluminum, iron in the ferric state, and chromium, the oxides 
of which exhibit weak basic properties and fail to combine with car- 
bonic acid, but are precipitated as hydroxides when their soluble 
salts are acted upon by alkali carbonates. 

The object of using hot solutions of the two salts and of adding 
the alum solution slowly to the alkaline liquid is to prevent the for- 
mation of basic aluminum sulphate and to facilitate the complete 
removal of alkali and sulphuric acid, which would be persistently 
retained by the precipitated hydroxide if the precipitation took place 
in the presence of an excess of alum. The use of hot liquids also 
facilitates the elimination of the carbon dioxide. 

Drying the precipitate at a moderate temperature is desirable to 
insure a smooth product, as a high heat would cause partial decom- 
position and a gritty powder. 

Aluminum Sulphate. A1 2 (S0 4 ) 3 + 1 6H 2 0. This salt is prefer- 
ably prepared for medicinal purposes by dissolving freshly prepared 



484 PHARMACEUTICAL CHEMISTRY. 

aluminum hydroxide in a sufficient quantity of sulphuric acid prop- 
erly diluted with water. An excess of acid should be avoided, as 
also an excess of the hydroxide; in the event of the latter, basic 
sulphates are likely to be formed. 100 Gm. of aluminum hydroxide 
(obtained from 607.33 Gm. of official alum) require 188.31 Gm. of 
absolute, or 203.58 Gm. of official sulphuric acid to form a normal 
salt. The gelatinous hydroxide will dissolve quite readily, and the 
solution having been filtered is evaporated on a water-bath until a 
crystalline residue is obtained. 

Aluminum sulphate contains about the same percentage of water 
of crystallization as official alum, but is far more soluble (about 8 
times) than the latter. 

Besides the official aluminum compounds the following is sometimes 
used : 

Solution of Aluminum Acetate. This preparation is recog- 
nized in the German Pharmacopoeia, aud is prepared by addiug 360 
Gm. of 30 per cent, acetic acid to a solution of 300 Gm. of alumi- 
num sulphate in SCO Cc. of water, and afterward introducing, in 
small portions at a time, a mixture of 130 Gm. of calcium car- 
bonate in 200 Cc. of water. The whole operation must be con- 
ducted in a cool place and the mixture be allowed to stand at rest 
for 24 hours, when the clear liquid may be removed with the aid of 
a siphon. The solution contains about 7.5 or 8 per cent, of basic 
aluminum acetate of the composition, Al 2 (OH) 2 (C 2 H 3 4 ) 4 . The re- 
action taking place !n the foregoing process may be illustrated thus : 
(Al 2 (S0 4 ) 3 +16HX))+4HC 2 H 3 0,4-3CaC0 3 = Al 2 (OH) 2 (C 2 H 3 2 ) 4 + 
3CaS0 4 -r3C0 2 -H7H 2 0. 



The Compounds of Cerium. 

Cerium Oxalate. Ce 2 (C 2 4 ) 3 +9H0 2 . This salt is prepared 
from the mineral cerite by a somewhat complicated process, on ac- 
count of the presence of two other metals, lanthanum and didymium, 
which are intimately associated with cerium as silicates. The pow- 
dered mineral is digested with sulphuric acid, the mass dried and 
treated with diluted nitric acid and hydrogen sulphide to remove 
copper and other metals. The cerite metals are next precipitated by 
means of oxalic acid, and the mixed oxalates, after the addition of 
magnesium carbonate, are calcined and the residue dissolved in a 
small quantity of concentrated nitric acid. The solution is poured 
into a large quantity of water containing about one-half per cent, 
of sulphuric acid, whereby the cerium is precipitated as yellow eerie 
sulphate, while lanthanum and didymium, together with the mag- 
nesium, remain in solution. The eerie sulphate is dissolved in sul- 
phuric acid and reduced to cerous sulphate, by means of sodium 



THE COMPOUNDS OF ALUMINUM AND CERIUM. 485 

thiosulphate, after which it is precipitated, as cerous oxalate, with 
oxalic acid and dried. 

Pure cerium oxalate is white, but the commercial article is fre- 
quently of a pink color, due to the presence of didymium, which 
may be detected by heating the suspected salt to redness, when a 
reddish-yellow residue of eerie oxide should be obtained, didymium 
imparting a brown color, as stated in the official test. 

Among the non-official salts of cerium, the nitrate, Ce(N0 3 ) 3 -j- 
6H 2 0, has been used to some extent. It may be conveniently made 
by decomposing cerous sulphate with barium nitrate, and possesses 
the advantage of being freelv soluble in water and alcohol. 



CHAPTEE XLVII. 

THE COMPOUNDS OF LEON. 

There is do class of inorganic compounds, excepting the official 
preparations of the alkalies, more extensively employed in medicine 
than those of iron ; they must therefore be considered as among the 
most important in the study of pharmacy. The Pharmacopoeia rec- 
ognizes, besides iron in the metallic form, no less than 38 different 
preparations of the same, of which 12 are liquid. Chemists have 
grouped all compounds of iron into two classes, designated as ferrous 
and ferric compounds respectively, which differ from each other in 
striking physical and chemical properties ; this distinction has also 
been maintained in the official titles of the iron salts and their solutions. 
Ferrous compounds, in which iron is bivalent, are, when not anhy- 
drous, of a green color, with one exception, the yellow oxalate, and 
form a blue precipitate of ferrous ferricyanide, Fe 3 (Fe(CN) 6 ) 2 , known 
as Turnbull's Blue, w T ith solution of potassium ferricyanide ; ferric 
compounds, in which iron is trivalent, on the other hand, are char- 
acterized by a reddish- or yellowish -brown color and form a blue 
precipitate of ferric ferrocyanide, Fe 4 (Fe(CJSi) 6 )3, known as Prussian 
Blue, with solution of potassium ferrocyanide. 

The following is a list of the official preparations of iron, divided, 
for convenience, into three classes : 

Official English Name. Official Latin Name. 

Metallic Iron. 

Iron, Ferrum. 

Eeduced Iron, Ferrum Eeductum. 

Ferrous Compounds. 

Ferrous Sulphate, Ferri Sulphas. 

Dried Ferrous Sulphate, Ferri Sulphas Exsiccatus. 

Granulated Ferrous Sulphate, , Ferri Sulphas Granulatus. 

Mass of Ferrous Carbonate, Massa Ferri Carbonatis. 

Saccharated Ferrous Carbonate, Ferri Carbonas Saccharatus. " 

Pills of Ferrous Carbonate, Pilulse Ferri Carbonatis. 

Ferrous Lactate, Ferri Lactas. 

Pills of Ferrous Iodide, Pilulse Ferri Iodidi. 

Saccharated Ferrous Iodide, Ferri Iodidum Saecharatum. 

Syrup of Ferrous Iodide, Syrupus Ferri Iodidi. 

Compound Iron Mixture, Mistura Ferri Composita. 

Ferric Compounds. 

Ferric Ammonium Sulphate, Ferri et Ammonii Sulphas. 

Ferric Chloride, Ferri Chloridum. 

Ferric Citrate, Ferri Citras. 

Ferric Hydrate, Ferri Oxidum Hydratum. 



THE COMPOUNDS OF IRON. 487 

Ferric Hydrate with Magnesia, Ferri Oxidum Hydratum cum Magnesia. 

Ferric Hypophosphite, Ferri Hypophosphis. 

Ferric Valerianate, Ferri Valerianas. 

Iron and Ammonium Citrate, Ferri et Ammonii Citras. 

Iron and Ammonium Tartrate, Ferri et Ammonii Tartras. 

Iron and Potassium Tartrate, Ferri et Potassii Tartras. 

Iron and Quinine Citrate, Ferri et Quinkme Citras. 

Soluble Iron and Quinine Citrate, Ferri et Quinina? Citras Solubilis. 

Iron and Strychnine Citrate. Ferri et Strychnine Citras. 

Soluble Ferric Phosphate, Ferri Phosphas Solubilis. 

Soluble Ferric Pyrophosphate, Ferri Pyrophosphas Solubilis. 

Solution of Ferric Acetate, Liquor Ferri Acetatis. 

Solution of Ferric Chloride, Liquor Ferri Chloridi. 

Solution of Ferric Citrate, Liquor Ferri Citratis. 

Solution of Ferric Nitrate, Liquor Ferri Nitratis. 

Solution of Ferric Subsulphate, Liquor Ferri Subsulphatis. 

Solution of Ferric Sulphate, Liquor Ferri Tersulphatis. 

Solution of Iron and Ammonium Liquor Ferri et Ammonii Acetatis. 

Acetate, 

Tincture of Ferric Chloride, Tinctura Ferri Chloridi. 

Iron Plaster, Emplastrum Ferri. 

Troches of Iron. Trochisci Ferri. 

Bitter Wine of Iron, Vinum Ferri Amarum. 

Wine of Ferric Citrate, Vinum Ferri Citratis. 

Iron. Fe. The kind of metallic iron recognized in the Pharma- 
copoeia is that occurring in the form of soft, bright wire. It should 
be free from rust and the commercial article, as it has usually been 
coated with grease or paraffin oil to protect it from moisture, must 
be thoroughly cleaned before it is used for pharmaceutical purposes. 
The kind of iron wire known in the trade as card-teeth, obtained as 
clippings aud waste from the manufacturers of cotton cards, is usually 
preferred on account of its convenient form and general good quality; 
sometimes, however, card-teeth of a very inferior grade are sold and 
require careful garbling and subsequent washing to remove grease 
and dirt. 

Reduced Iron. This preparation represents more or less pure 
metallic iron in a fine state of division, obtained by reduction of 
ferric oxide with hydrogen gas. Ferric hydroxide (see Ferric Hy- 
drate) is first dried, whereby it is changed to oxyhydrate, and then 
placed in an iron reduction tube so arranged that the same can be 
heated to dull redness, while a current of hydrogen gas, previously 
washed and dried by being passed through a moderately strong solu- 
tion of potassium permanganate and afterward sulphuric acid, is 
constantly passed through it. The reducing action of hydrogen on 
ferric oxide may be illustrated by the following equation : Fe 2 3 -f- 
H 6 =Fe 2 + 3H 2 Q. The supply of hydrogen is kept up as long as 
any oxygen is left, as shown by the escape of aqueous vapor from 
the tube. When reduction is complete the tube and contents are 
allowed to cool slowly, while a slow stream of hydrogen is continued 
until the temperature has been reduced to that of the air ; this is 
necessary, otherwise the hot, finely divided iron will be readily re- 



488 PHARMACEUTICAL CHEMISTRY. 

oxidized by the air, as in that condition its avidity for oxygen is 
very marked. 

The quality of reduced iron depends, of course, upon the purity of 
the ferric hydroxide and the temperature employed. When ferric 
oxide is heated to 280° or 300° C. (536°-572° F.) iu a stream of 
hydrogen, it is converted into ferroso-ferric oxide, Fe 3 4 ,(3Fe 2 3 -f- 
H 2 =2Fe 3 4 or 2(FeO-f Fe 2 3 )+H 2 0), but metallic reduction does 
not occur until a temperature of 400° C. (752° F.) and over is 
reached. A bright red heat, however, is not employed, as it causes 
a dense, compact product, which is not desirable ; therefore the com- 
mercial article, although a lighter powder, is usually contaminated 
"with imperfectly reduced oxide. 

Reduced iron should be free from lustre and of a grayish color, 
and, when treated with warm diluted sulphuric or hydrochloric acid, 
should leave not more than 1 per cent, of insoluble residue. Its 
value is based upon the proportion of metallic iron present ; the U. S. 
Pharmacopoeia demands 80 per cent., w r hile the German Pharma- 
copoeia insists upon 90 per ceut. Frequent examinations of the com- 
mercial products have disclosed the fact that much inferior reduced 
iron is dispensed by pharmacists, but few samples coming up to the 
official requirements. 

The Pharmacopoeia directs that the valuation of reduced iron shall 
be made with mercuric chloride and potassium permanganate, the 
assay being subsequently confirmed by means of potassium iodide 
and sodium thiosulphate. The test involves several reactions, as 
follows : 1. When reduced iron is digested with solution of mer- 
curic chloride, the latter salt is reduced to mercurous chloride by the 
metallic iron present, ferrous chloride being formed at the same time ; 
thus, 2HgCl 2 +Fe=Hg 2 Cl 2 +FeCl 2 . 2. Ferrous chloride, when 
treated with potassium permanganate and sulphuric acid, is con- 
verted into ferric sulphate and chloride; thus, 10 FeCl 2 +2KMn0 4 
+ 8H 2 S0 4 = 2Fe 2 (S0 4 ) 3 -j-3Fe 2 Cl 6 + 2KC1 + 2MnS0 4 + 8H 2 0. 3. 
This mixture, digested with potassium iodide, liberates iodine, which 
is held in solution by the excess of potassium iodide, at the same time 
forming potassium sulphate and chloride, while the ferric salts are 
reduced to the ferrous state; thus, 2Fe 2 (SO 4 ) 3 +3Fe 9 Cl 6 -j-10KI= 
I 10 + 4FeSO 4 +6FeCl 2 +2K 2 SO 4 + 6KCl. These reactions plainly 
show that, for each atom (or 55.88 parts) of metallic iron present 
in the reduced iron, one atom (or 126.53 parts) of iodine is finally 
liberated, and, as each Cc. of decinormal sodium thiosulphate solu- 
tion w 7 ill decolorize 0.012653 Gm. of iodine, it must correspond 
also to 0.005588 Gm. of metallic iron. The second equation shows 
that 2 molecules of potassium permanganate are capable of oxidiz- 
ing 10 molecules of ferrous salt, representing 10 atoms of iron ; 
therefore each Cc. T \KMn0 4 solution, containing 0.0031534 Gm. 
KMn0 4 , must correspond to 0.005588 Gm. of metallic iron. 

In the official test, the 10 Cc. of filtrate directed to be used repre- 
sent 0.056 Gm. of reduced iron, as 0.56 Gm. was used to obtain 100 



THE COMPOUNDS OF IRON. 489 

Cc. of liquid, aud each Ccy^KMuOj solution necessary to obtain a 
permanent pink coloration (showing complete oxidation) indicates 
0.005588 Gra. or 10 per cent, of metallic iron ; at least 8 Cc. will 
be required if the sample is of the quality officially required. 

Ferrous Sulphate. FeSO^-f 7H 2 0. This salt, from which 
numerous other ferrous as well as ferric compounds are made, is ob- 
tained, for medicinal purposes, by acting on clean iron wire with 
diluted sulphuric acid, aiding the reaction with a little heat. The 
newly formed ferrous sulphate enters into solution and hvdrogen gas 
is eliminated, thus: Fe 2 -[-2H,SO,= 2FeS0 4 + H 4 ; the salt is prone 
to oxidation if a strictly neutral solution be evaporated, hence a little 
free sulphuric acid is usually left in the liquid, which is then concen- 
trated and crystallized. 

The official ferrous sulphate contains 45.32 per cent, of water of 
crystallization, a portion of which is lost by efflorescence upon expo- 
sure to dry air; when exposed to moist air the salt undergoes oxida- 
tion, indicated by the formation of a brownish-yellow basic ferric 
sulphate. The crystals should therefore be preserved in well-stop- 
pered bottles. 

The commercial crude ferrous sulphate known as " copperas/' is 
always more or less impure and not suited for pharmaceutical pur- 
poses. The Pharmacopoeia requires absolute purity for the official 
salt, which is determined volumetrically with decinormal potassium 
permanganate solution. Each molecule of potassium permanganate is 
capable of converting 5 molecules of ferrous sulphate into ferric sul- 
phate ; thus, 10(FeSO 4 -f 7H,0)-f2KMn0 4 + 8H,SO,= 5Fe 9 (SOJ 3 
+ K 2 S0 4 + 2MnSO, -f- 78H 2 ; hence each Cc^-KMnO, solu- 
tion corresponds to 0.027742 Gm. of crystallized pure ferrous sul- 
phate, and not less than 50 Cc. will be required for 1.39 Gm., as 
1.39-^-0.027742=50.1+. 

Dried Ferrous Sulphate. Approximately 2FeS0 4 -f 3H 2 0. 

The Pharmacopoeia directs dried ferrous sulphate to be prepared by 
allowing the crystallized salt to effloresce at a gentle heat and then 
exposing it in a dish to the heat of a boiling- water bath until reduced 
to about 65 per cent, of its original weight. This procedure does 
not render the salt anhydrous, for, even at 115° C. (239° F.) 6.48 
per cent, of water still remains, which requires a heat of nearly 300° 
C. (592° F.) for complete expulsion ; at the latter temperature the 
ferrous sulphate is likely to undergo decomposition. 

Dried ferrous sulphate may be conveniently employed for pill- 
masses and other purposes, in place of the crystallized salt, in the 
proportion of 0.65 Gm. for 1 Gm. or (or 6.5 grains for 10 grains) of 
the latter. 

Granulated Ferrous Sulphate. ( FeS0 4 — 7H 2 C This salt 
differs from official ferrous sulphate in being in the form of a crystal- 



490 PHARMACEUTICAL CHEMISTRY. 

line powder instead of large crystals, containing, however, the same 
amount of water. It is of a much paler color than the crystals, and, 
owing to its mode of preparation, is less liable to oxidation. The 
washing of the crystalline powder with alcohol is for the purpose of 
removing the acid and uncombined water as completely as possible, 
thus facilitating drying ; a more effectual plan is to pour the acid 
solution, when cold, into one-half its volume of alcohol, whereby the 
salt is precipitated and can then be drained on a strainer and washed 
with diluted alcohol until free from acid. Rapid drying in direct 
sunlight is advantageous, as it prevents oxidation. 

Granulated ferrous sulphate presents a convenient form for dis- 
pensing purposes. 

Mass of Ferrous Carbonate. This preparation has already 
been considered on page 334, which see. The reaction occurring be- 
tween the two solutions of ferrous sulphate and sodium carbonate 
may be illustrated thus : (FeSO, + 7H 2 0) + (Na,C0 3 + 10H 9 O) = 
FeCO s + Na 2 S0 4 + 17H 2 0, showing that 277.42 parts of crystal- 
lized ferrous sulphate will yield 115.73 parts of ferrous carbonate; 
100 Gm., therefore, should yield about 42 Gm. if none of the pre- 
cipitate be lost, as 277.42 : 115.73 : : 100 : 41.71. The object of 
the addition of syrup to the iron solution and subsequent washing of 
the precipitate with sweetened water is to prevent oxidation of the 
iron salt, as far as possible. 

Saccharated Ferrous Carbonate. Although but little used 
at the present time, this preparation is still recognized in the Phar- 
macopoeia. It closely resembles the preceding preparation, except 
that it occurs in powder form and is directed to contain a minimum 
limit of ferrous carbonate. The official directions are to pour a hot 
solution of 50 Gm. of ferrous sulphate into a warm solution of 
35 Gm. of sodium bicarbonate contained in a flask, aiding decom- 
position by rotating the vessel. The precipitate is repeatedly washed 
w r ith hot water until the newly formed sodium sulphate has been re- 
moved, after which the precipitate is drained, mixed with 80 Gm. of 
sugar, evaporated to dryness, reduced to powder, and incorporated 
with sufficient sugar to make the finished product weigh 100 Gm. 
The reaction differs from that stated above in being accompanied by 
evolution of carbon dioxide ; thus, (FeSO, + 10H 2 O)+ 2NaHC0 3 = 
FeCO s -j- Na 2 SO, -f C0 2 -f 11H 2 0. As the powder readily oxidizes 
if exposed to air, it must be preserved in tightly stoppered bottles. 

The Pharmacopoeia requires the presence of at least 15 per cent, 
of ferrous carbonate, determined by dissolving 1.16 Gm. of the 
powder in diluted sulphuric acid and titrating with potassium per- 
manganate. Ferrous sulphate is formed and the subsequent reaction 
is identical with that already explained under that head. Each Cc. 
•^ KMn0 4 solution, corresponding to 0.027742 Gm. FeSO, + 
10H 2 O, is also equivalent to 0.011573 Gm. FeCQ 3 ; hence 15 Cc. 



THE COMPOUNDS OF IRON. 491 

will be required to show 15 per cent, of 1.16 Gm., for 15 per cent, 
of 1.16 is 0.174 and 0.011573 X 15 = 0.173585. 

Ferrous Lactate. Fe(C 3 H 5 3 ) 2 -f- 3H 2 0. This salt may be 
prepared by double decomposition between solutions of calcium lac- 
tate aud ferrous sulphate, the newly formed calcium sulphate being 
completely removed by addition of alcohol ; the filtrate is finally 
evaporated and crystallized. It may also be obtained by digesting 
pure iron wire with diluted lactic acid until reaction ceases, then 
filtering, concentrating, and crystallizing the solution. In the first 
process the reaction is as follows : Ca(C 3 H 5 3 ) 2 .5H 2 0-f FeS0 4 .7H 2 
= Fe(C 3 H 5 3 ) 2 -f CaSCXt -f- 12H 2 0; while, in the second process, 
ferrous lactate is formed with elimination of hydrogen ; thus, Fe 2 + 
4HC 3 H 3 3 = 2Fe(C 3 H 5 3 ) 2 + H r 

Two varieties of ferrous lactate occur in commerce, one in well-de- 
fined crystalline crusts and another in the form of a crystalline powder. 
The first-named is to be preferred for pharmaceutical purposes and is 
the kind officially recognized ; it is, as a rule, more soluble and less 
likely to have become oxidized. Ferrous lactate should be preserved 
in tightly stoppered bottles, in a dry place, as, upon exposure to 
moist air, it is gradually converted into a ferric salt. 

The Pharmacopoeia demands that ferrous lactate shall, after hav- 
ing been moistened with nitric acid, yield, upon ignition, not less 
than 27 nor more than 27.8 per cent, of an insoluble residue, con- 
sisting of ferric oxide only, which indicates a pure salt of the above 
composition, as 574.68 Gm. of crystallized ferrous lactate will yield 
159.64 Gm. of ferric oxide, which is equivalent to 127.78 per cent. 

Saccharated Ferrous Iodide. The Pharmacopoeia directs 
that this preparation shall be made by first preparing a solution of 
ferrous iodide, which is then evaporated, with the addition of sugar 
of milk, to dryness ; finally some reduced iron is added and enough 
sugar of milk to bring the weight of the finished product to 100 Gm. 
for every 17 Gm. of iodine employed. The mixture is to be reduced 
to powder and carefully protected from air and light. 

When iodine is brought together with an excess of iron, in the 
presence of a small quantity of water, the two elements combine 
with the development of heat, forming ferrous iodide, which dis- 
solves the remainder of the iodine present and gradually the color of 
the solution changes to pale green, when all iodine has united with 
iron to form the compound Fel 2 . Unless the concentrated solution 
be mixed with some sugar of milk before evaporation to dryness, the 
resulting product will be a deliquescent mass, difficult to remove 
from the capsule. Reduced iron, to the extent of 1 per cent, of the 
proposed weight of the finished product, is added to prevent, or at 
least retard, subsequent decomposition. The finished powder is very 
hygroscopic and by no means permanent, and there appears to be 
little or no advantage in this preparation over the syrup of ferrous 



492 PHARMACEUTICAL CHEMISTRY. 

iodide, although it contains twice as much of the iron salt as the 
latter. 

The valuation of saccharated ferrous iodide is made volumetrically 
by means of silver nitrate solution, silver iodide being precipitated 
and ferrous nitrate remaining in solution. In the official test, an 
unknown excess of the silver solution is added, which is determined 
by means of potassium sulphocyanate iu the presence of nitric acid 
and ferric alum. The addition of nitric acid prevents the coloration 
of the liquid by the iron, and is always employed when silver nitrate 
is titrated by means of potassium sulphocyanate with ferric alum as 
an indicator. 

In the official determination of ferrous iodide, both in the saccha- 
rated powder and the syrup of that name, several distinct reactions 
occur, namely : 

1. All the iodine present is precipitated "as silver iodide; thus, 
Fel 2 + 2AgN0 3 = 2AgI + Fe(N0 3 ) 2 . _ 

2. The excess of silver nitrate added is determined by precipitation 
as white silver sulphocyanate; thus, AgNO s + KSCN = AgSCN 
+ KN0 3 . 

3. After all silver has been precipitated, the least further addition 
of potassium sulphocyanate solution produces a permanent reddish- 
brown tint, due to the reaction with ferric alum and consequent for- 
mation of ferric sulphocyanate ; thus, Fe 2 (NH 4 ).,(S0 4 ) 4 +6KSCN = 
Fe 2 (SCN) fi + (NHj 2 S0 4 + 3K 2 S0 4 . 

The first equation indicates that each Cc. of yw AgN0 3 solution 
represents 0.015477 Gm. of Fel 2 ; as the T N F AgN0 3 and ^KSCN 
solutions exactly decompose each other, measure for measure, the 
number of Cc. of the latter necessary before a permanent brownish 
tint appears, subtracted from the number of Cc. of silver solution 
first added, leaves the number of Cc. of t K q- AgN0 3 solution actually 
used for precipitation of the iodine, which number multiplied by 
0.015477 indicates the weight of ferrous iodide preseut in the 
sample. If 1.55 Gm. of saccharated ferrous iodide be used for the 
test, as directed, 20 Cc. (22-2) T N T AgN0 3 solution will therefore be 
required to show 20 per cent, of Fel 2 , for 20 per cent, of 1.55 is 
0.31 and 0.015477 X 20 = 0.30954. 

Syrup of Ferrous Iodide. As already stated on page 224, 
this preparation is made by mixing a freshly prepared solution of 
ferrous iodide with simple syrup in such proportions that the mix- 
ture shall contain 10 per cent, by weight of the salt. In the preced- 
ing paragraph the preparation of solution of ferrous iodide has been 
explained. No attempt should be made to add the solution to the 
syrup until a pale-green color, entirely free from brown, has been 
acquired and all odor of iodine has been lost. The solution, heated 
to boiling, should be filtered rapidly in a covered funnel, the point of 
which dips below the surface of the syrup, in order to avoid contact 
with the air as far as possible. 



THE COMPOUNDS OF IRON. 493 

Syrup of ferrous iodide is proue to decomposition if exposed to 
air, resulting in the oxidation of the ferrous into ferric salt, with 
gradual liberation of iodine. When thus changed, it can be restored 
to its original condition by exposing it to direct sunlight. The syrup 
should be preserved in small, completely filled, and tightly stoppered 
vials. Various additions have been suggested to prevent a change 
of the finished syrup, such as bright iron wire, glycerin, citric acid, 
etc., but the best results thus far have been obtained by the use of 
pure glucose in place of one-half of the simple syrup required ; syrup 
thus prepared has been exposed in half-filled pint bottles to diffused 
daylight for several months, by G. H. Klie, of St. Louis, without 
undergoing any apparent change. 

The valuation of syrup of ferrous iodide is conducted in exactly 
the same manner as given and explained under the preceding article. 
As the syrup contains only 10 per cent, of ferrous iodide, only one- 
half as much decinormal silver nitrate solution will be required as 
for a like weight of the saccharated powder. 

Compound Iron Mixture. This preparation has already been 
considered on page 306 (which see). When freshly made, each cubic 
centimeter contains about 0.0025 Gm. of ferrous carbonate (about 
1.14 grains in each fluidounce. 

Ferric Ammonium Sulphate. Fe 2 (NH 4 ) 2 (S0 4 ) 4 -j-24H 2 0. This 
salt, resembling ordinary alum somewhat in chemical constitution, is 
obtained by dissolving ammonium sulphate in a boiling hot solution 
of ferric sulphate and setting the liquid aside to crystallize. If a 
slight addition of sulphuric acid be made to the solution, the crystals 
obtained will be more perfect in form and color. 

The crystals are liable to deterioration by exposure to air and 
heat, hence they should be preserved in tightly stoppered bottles, in 
a cool place; when recently obtained or carefully preserved, they are 
of a beautiful pale-violet or hyacinthine color, but their solution in 
water is of a brownish-yellow color, gradually changing to red and 
depositing a basic salt. 

Ferric ammonium sulphate, also known as ferric alum or ammonio- 
ferric alum, should contain not less than 11.6 per cent, of metallic 
iron in the form of ferric sulphate. The iron is determined volu- 
metrically by the iodometric method, which has already been explained 
in connection with the valuation of reduced iron. The addition of 
hydrochloric acid, prescribed by the Pharmacopoeia, is not essential 
for the reaction, but facilitates the same by converting the ferric sul- 
phate into chloride, the latter salt decomposing potassium iodide 
more readily than the former. Since each Cc. of T ^- Na 2 S 2 3 solution 
represents 0.005588 Gm. of metallic iron, not less than 11.6 Cc. 
should be required to discharge the color of iodine completely in the 
official test, 0.56 Gm. of the salt being used ; for 11.6 per cent, of 
0.56 is 0.06496 and 11.6 X 0.005588 = 0.064821. 



494 PHARMACEUTICAL CHEMISTRY. 

Ferric Chloride. Fe 2 Cl 6 + 12H 2 0. The official directions 
for preparing this salt consist in maceration of bright iron wire 
with about 3J times its weight of hydrochloric acid, moderatel) T 
diluted with water, oxidation of the resulting solution by means of 
nitric and hydrochloric acids and finally, after addition of a little 
more hydrochloric acid, evaporating the liquid to a definite weight 
and allowing it to crystallize. 

The mixture of iron 15 Gm., hydrochloric acid 54 Gm. and water 
25 Gm., is kept in a moderately warm place as long as effervescence 
continues, which is due to the escape of hydrogen, the ferrous chlor- 
ide formed dissolving in the water ; the equation, Fe 2 -f- 4HC1 = 
2FeCl 2 + H 4 , illustrates the reaction. Not all the iron is dissolved, 
an excess being purposely directed iu the Pharmacopoeia to facilitate 
the reaction. The object of heating the liquid to the boiling-point 
before filtration and washing the flask and filter with hot water, is to 
insure complete solution of all ferrous chloride formed, as it some- 
times crystallizes, owing to the density of the solution, especially in 
cold weather. The further addition of hydrochloric acid 28 Gm., 
should be made without delay, so as to avoid the formation and de- 
posit of ferric oxychloride, since the ferrous chloride solution is 
readily oxidized by the air. The liquid, which has now assumed a 
deep green color, is poured slowly into a porcelain dish containing 
8 Gm. of nitric acid, and then warmed. A change in color to reddish- 
brown at once occurs, owing to the conversion of the ferrous into 
ferric chloride, accompanied by effervescence and escape of red fumes, 
which may be illustrated bv the following equation : 6FeCl 2 -j- 6HC1 
+ 2HN0 3 = 3Fe 2 Cl 6 + 2NO + 4H 2 0. The red fumes are due to 
nitrogen tetroxide, N0 2 or N 2 4 , resulting from a union of nitric 
oxide, NO, with some of the oxygen of the air. 

It frequently happens that the color of the liquid remains blackish 
for some time ; this is due either to a union of ferrous chloride with 
nitric oxide, in which case it disappears upon further heating as oxi- 
dation progresses, or, it may be, to an insufficiency of nitric acid and 
consequent imperfect oxidation. 

To remove all nitrogen compounds, the liquid is heated on a sand- 
bath until free from nitrous odor, after which it is tested for ferrous 
salt, as prescribed, and, if more nitric acid is necessary, this should be 
added drop by drop to the hot liquid and only as long as efferves- 
cence results, as an excess of nitric acid is not readily removed. If 
ferrous salt is found absent, a test for nitric acid should be made and, 
if present, the liquid must be boiled on a sand-bath until entirely 
free therefrom ; this is preferably done with careful addition of small 
quantities of hydrochloric acid, which facilitates the expulsion of 
nitric acid by decomposing it, and prevents the formation of oxy- 
chloride. Should the liquid, upon boiling to free it from nitric acid, 
separate a blackish-brown deposit on the sides or bottom of the dish, 
this would indicate ferric oxychloride, which can only be overcome 
by careful addition of hydrochloric acid to the hot liquid until a one- 



THE COMPOUNDS OF IE OX. 495 

per cent, solution of the latter in water remains clear upon boiling 
and cooling. 

The final addition of 5 6m. of hydrochloric acid to the liquid is 
for the purpose of preventing the formation of ferric oxychloride by 
having an excess of the acid present. Although the Pharmacopoeia 
directs the addition of water, it is often found necessary, partic- 
ularly if official acids have been used aud the process carefully con- 
ducted, to evaporate the solution in order to obtain 60 Gm. of liquid. 
Experience has shown that better results are obtained if a solution 
containing 60 per cent, of anhydrous ferric chloride be set aside to 
absorb the requisite amount of water for crystallization than if it be 
evaporated to the crystallizing point. The theoretical yield of the 
official formula is about 65 Gm. (64.6) of the crystallized salt, pro- 
vided hydrochloric acid of official strength has been employed. 

Ferric chloride is a very deliquescent salt and, upon exposure to 
sunlight, is gradually reduced to ferrous chloride, hence it must be 
preserved in tightly stoppered bottles protected from light ; corks 
•coated with paraffin are preferable to glass stoppers. 

The Pharmacopoeia requires that 20 per cent, of metallic irou 
shall be represented in the salt, which is determined by the iodo- 
metric method already explained on page 488. The equation (Fe 2 Cl 6 
+ 12H 2 0) + 2KI = I 2 + 2FeCl 2 + 2KC1 shows that 539.5 parts 
of the official salt will liberate 253.06 parts of iodine and, as each Cc. 
y^-^Na 2 S 2 3 solution corresponds to 0.005588 Gm. of metallic iron, 
20 Cc. should be required to decolorize the iodine liberated by 0.56 
Gm. of crystallized ferric chloride of the above composition. 

Ferric Citrate. This preparation is obtained by evaporating 
the official solution of ferric citrate to a syrupy consistence and then 
spreading the liquid on glass plates by means of a broad flat brush, 
and drying, in suitable drying-closets, at a moderate temperature, so 
that the salt will be obtained in perfect scales. A temperature ex- 
ceeding 60° C. (140° F.) should not be employed, otherwise the salt 
will be slowly reduced to a ferrous compound. The usual yield is 
from 42 to 44 per cent, of the weight of solution evaporated, and 
failure to obtain perfect scales may be due to insufficient concentration 
of the liquid before spreading it on glass or too high a temperature 
in drying. 

Although all scale salts of iron contain water of hydration, the 
amount present varies, not only for different salts, but also for differ- 
ent lots of the same salt, and is dependent upon the temperature 
employed in scaling, subsequent exposure, etc. ; no definite formula 
expressing the composition of the scale salts of iron therefore 
can be given. Carefully prepared ferric citrate was found by 
F. B. Power to contain 31.9 per cent, of water, which would corre- 
spond very nearly to the formula, Fe 2 (C 6 H.0 7 ) 2 -f 12H 2 0, while 
some commercial samples contained but 8.4 and 15.2 per cent. In 
estimating the water of hydration, a temperature of 100° C. (212° F.) 



496 PHARMACEUTICAL CHEMISTRY. 

should not be exceeded, as, beyond this temperature, decomposition 
of the salt is apt to occur. 

Ferric citrate is slowly but completely soluble in cold water, and, 
for purposes of solution, the so-called soluble citrate of iron (see Iron 
and Ammonium Citrate) is therefore preferable, but the plain ferric 
citrate should always be used for pill-masses and similar purposes. 

The Pharmacopoeia directs that the iron present in the various 
scale salts of iron shall be determined by the iodometric method, as 
in the case of ferric chloride, the respective iron salts being first con- 
verted into ferric chloride by digestion with hydrochloric acid. In 
the case of ferric citrate the equivalent of 16 percent, of metallic iron 
is demanded. 

Feeric Hydrate or Hydeoxide. Fe 2 (OH) 6 or Fe(OH) 3 . The 
official directions for making this compound, are to pour 10 volumes 
of solution of ferric sulphate into 11 volumes of ten per cent, ammo- 
nia water, both liquids having been previously largely diluted with 
water. The process should not be reversed, otherwise basic ferric 
sulphate may be formed. Large dilution with water and a cool 
temperature are essential to insure the precipitation of a fully hy- 
drated oxide, as indicated by the above formula. Ammonia water is 
purposely used in excess so as to insure complete decomposition of the 
ferric sulphate ; the reaction occurring is as follows : Fe 2 (S0 4 ) 3 + 
6NH.OH = Fe 2 (OH) 6 + 3(NH 4 ) 2 SO,. 

The bulky precipitate subsides very slowly and must be repeatedly 
washed with cold water until the reaction for the presence of sul- 
phates ceases and the odor of ammonia is lost. It is finally drained on 
a well-wetted strainer and mixed with sufficient cold water to make 
the weight of the finished product 2500 grammes for every liter of 
solution of ferric sulphate used. In this condition the ferric hy- 
droxide keeps fairly well for a time, if heat and light be excluded, 
but it gradually undergoes change, being converted into the compound, 
Fe 2 2 (OH) 2 , of a more decided reddish tint, and is then no longer 
suitable as an antidote, having lost its power to combine with weak 
acids. 

Ferric hydroxide, freshly precipitated, is used in the preparation 
of certain official iron solutions and, when dried at a temperature 
not exceeding 80° C. (176° F.), as oxyhydrate, in the preparation of 
plaster and troches of iron. 

Ferric Hydrate with Magnesia. This preparation is to be 
much preferred to the preceding as an antidote in cases of poisoning 
by arsenic, as it can be made available at very short notice, not re- 
quiring tedious preparation. It consists of a mixture of ferric and 
magnesium hydroxides suspended in a dilute solution of magnesium 
sulphate and is made by adding a dilute solution of ferric sulphate 
to a dilute mixture of calcined magnesia and water ; the mixture is 
well shaken and is then ready for use. 



THE COMPOUNDS OF IRON. 497 

The Pharmacopoeia, with the view of economizing time in cases ot 
emergency, recommends that the dilate solution of ferric sulphate 
and the mixture of magnesia and water be always kept on hand, 
ready for immediate use. The former consists of 50 Cc. of the offi- 
cial solution of ferric sulphate and 100 Cc. of water ; the latter, of 
10 Gm, of calcined magnesia added to 750 Cc. of water. 

Ferric Hypo-phosphite. This salt can be conveniently prepared 
by a method proposed by F. X. Moerk, in 1889, which consists in 
placing 30 Gm. of calcium hypophosphite in a flask with 100 Cc. of 
distilled water and adding gradually 49.5 Gm. of the official ferric 
chloride solution, shaking well after each addition. The mixture is 
allowed to stand for three days, with frequent agitation, then filtered 
and washed until all calcium has been removed. The yield by this 
method is large and the product fully up to the official requirements. 

It was at one time suggested that ferric hypophosphite could be 
made by mixing solutions of calcium hypophosphite and ferrous 
sulphate, removing the precipitated calcium sulphate by filtration and 
evaporating the solution of ferrous hypophosphite to dryness. It 
was supposed that the ferrous salt was, by oxidation during the 
evaporation, converted into ferric hypophosphite ; but, instead of the 
normal salt, a basic hypophosphite, Fe 2 0(PH 2 O 2 ) 4 , is obtained, for 
want of a sufficiency of acid, as is similarly the case with the official 
solution of ferric subsulphate. Double decomposition of solutions 
of ferric sulphate or chloride and sodium hypophosphite is also im- 
practicable, as the freshly precipitated ferric hypophosphite has been 
found quite soluble in water, thus considerable loss would be entailed 
during the necessary washing of the precipitate. 

Ferric hypophosphite is sparingly soluble in water, but dissolves 
readily in a warm strong solution of an alkali citrate and, in this 
form, is used in the preparation of certain syrups. 

The Pharmacopoeia requires the official salt to contain 98.1 per 
cent, of absolute Fe 2 (PH 2 2 ) 6 , which is determined volumetrically 
with potassium permanganate, as in the case of other hypophosphites. 
The following equation, 5Fe 2 (PH.A) 6 + 24KMn0 4 + 36H 9 S0 4 = 
5Fe 2 (PO 4 ) 2 +20H 3 PO 4 +12K 2 SO 4 +24MnSO 4 +36H 2 O, shows that 
2505.2 parts of ferric hypophosphite require 3784.08 parts of potas- 
sium permanganate for complete oxidation, hence each Cc. of 
^ KMn0 4 solution corresponds to 0.0020877 Gm. of Fe 2 (PH 2 2 ) 6 . 
In the official test, 0.1 Gm. of the salt being used, 47 Cc. (50-3) will 
be required to show 98.1 per cent., for 98.1 per cent, of 0.1 is 0.0981 
and 0.0020877 X 47 = 0.0981219. 

Ferric Phosphate, Soluble. The official phosphate of iron, 
which occurs in scale form and is soluble in water, must not be con- 
founded with the insoluble commercial article of a similar name. 
The latter is a slate-colored powder of variable composition, consist- 
ing of a mixture of insoluble ferrous aud ferric phosphates, obtained 

32 



498 PHARMACEUTICAL CHEMISTRY. 

by precipitation of a solution of ferrous sulphate by means of sodium 
phosphate and drying the resulting product. 

Soluble ferric phosphate is made, according to the Pharmacopoeia, 
by adding 11 parts of crystallized sodium phosphate to a solution of 
10 parts of ferric citrate in twice its weight of water, evaporating 
the resulting green-colored solution, at a temperature not exceeding 
60 C. (140 F.), to a syrupy consistence and spreading the same on 
glass plates, as in the case of ferric citrate. It is importaut that un- 
effloresced sodium phosphate be used, as officially directed, to avoid 
an excess of this salt, which would cause the scales to become opaque 
and white on standing. The salt should be preserved in tightly 
corked bottles, in a dark place, otherwise its color will gradually 
darken and its solubility be impaired. 

The exact composition of this salt cannot be stated, as it may be 
a mixture of ferric phosphate and sodium citrate or possibly a mix- 
ture of four salts, ferric aud sodium phosphates and ferric and sodium 
citrates, incomplete decomposition having taken place ; hence the 
name, sodio-citrophosphate of iron, is frequently applied to the prep- 
aration. 

The Pharmacopoeia requires that soluble ferric phosphate shall con- 
tain iron in combination corresponding to 12 per cent, of that metal. 

Ferric Pyrophosphate, Soluble. This preparation closely re- 
sembles the preceding compound, and is made in a similar manner, 
except that sodium pyrophosphate is used in place of the phosphate 
and that the sodium and iron salts are used in equal proportions. 
Prior to 1882 this preparation was made by precipitating a white 
ferric pyrophosphate, Fe 4 (P 2 7 ) 3 , from a solution of ferric sulphate 
by means of sodium pyrophosphate, dissolving this precipitate in solu- 
tion of sodium or ammonium citrate and concentrating and scaling 
the solution so obtained. The present official process yields a more 
satisfactory product. 

The composition of soluble ferric pyrophosphate is as uncertain as 
that of the preceding scale salt, hence no definite formula as to its 
constitution can be given. Like the soluble ferric phosphate, it must 
be carefully protected against exposure to air and light. The two 
preparations are both of a green color (the phosphate bright green, 
the pyrophosphate apple-green), but may be readily distinguished 
from each other by boiling some of the salt with sodium hydroxide 
solution, filtering, acidulating the filtrate with hydrochloric acid aud 
adding some magnesia test mixture (see U. S. Pharmacopoeia) and a 
slight excess of ammonia water ; in the case of the phosphate, a 
white crystalline precipitate of ammonium magnesium phosphate, 
NH 4 MgP0 4 , will occur, while the solution of the pyrophosphate will 
not be disturbed at all. 

Although ferric pyrophosphate in scales is usually known in com- 
merce simply as pyrophosphate of iron, it is best always to designate 
it as soluble pyrophosphate of iron, because the true ferric pyrophos- 



THE COMPOUNDS OF IRON. 499 

phate also occurs on the market (although rarely), in the form of a 
white insoluble powder. 

The amount of iron present in this preparation is required by the 
Pharmacopoeia to be equivalent to 10 per cent, of metallic iron. 
The method of determiuation differs from that designated for the other 
scale salts of iron, iu directing the addition of a much larger propor- 
tion of hydrochloric acid ; this is done to insure complete solution 
and conversion into chloride of the true ferric pyrophosphate, which 
is precipitated on the first addition of the acid. The use of a larger 
amount of acid also demands the subsequent addition of more water, 
so as to avoid any risk of decomposition of the potassium iodide by 
the strong acid itself. 

Ferric Valerianate. This salt is best obtained by double de- 
composition between cold solutions of ferric sulphate and sodium 
valerianate, washing the resulting precipitate with a little cold water 
and drying at a moderate temperature. The composition of ferric 
valerianate is variable, depending upon the care employed in washing 
the precipitate and the temperature at which, it is dried. The normal 
salt would have the composition, Fe 2 (C 5 H 9 2 ) 6 , but the commercial 
product is often mixed with basic salt, as shown by its increased 
yield of ferric oxide upon ignition. 

Ferric valerianate is rarely used in other than pill-form, although 
it is readily soluble in alcohol. Owing to the variable composition 
of the salt the Pharmacopoeia allows a variation of 5 per cent, in 
the amount of metallic iron represented, requiring the same to be not 
less than 15 nor more than 20 per cent. 

Iron and Ammonium Citrate. This preparation resembles the 
official ferric citrate, in appearance, but is far more readily soluble 
than it in cold water. It is obtained by mixing 10 volumes of solu- 
tion of ferric citrate with 4 volumes of 10 per cent, ammonia water, 
concentrating and scaling the solution exactly as in the case of ferric 
citrate. The resulting product must of necessity be of variable 
composition, both as regards the amount of water of hydration 
and also the relative proportions of ferric and ammonium citrates 
present. 

The official title, iron and ammonium citrate, would indicate a true 
double salt, which, when anhydrous, should be of uniform compo- 
sition ; such is not the case, however, and, as the Pharmacopoeia re- 
quires the compound to contain exactly the same relative amount of 
iron as the plain ferric citrate, there cannot be much ammonium 
citrate present. The name soluble ferric citrate appears more appro- 
priate and serves to distinguish it from the less soluble article. In- 
asmuch as ferric citrate is very rarely used in any other form than 
that of solution, it seems superfluous to have two preparations so 
nearly identical and differing from each other chiefly in degree of 
solubility. 



500 PHARMACEUTICAL CHEMISTRY. 

Iron and ammonium citrate is more hygroscopic than ferric citrate, 
and, upon exposure to air, rapidly loses ammouia and becomes less 
soluble, hence it must be preserved in tightly stoppered bottles ; 
light also has a deleterious effect upon it. If at any time the scale 
salt has suffered by age or careless exposure, ready solution can 
usually be effected by the cautious addition of a drop or two of am- 
monia water to the residue. 

Iron and Ammonium Tartrate. In the official formula for 
the manufacture of this scale salt, the first step is the preparation of 
ferric hydroxide from 100 Cc. of solution of ferric sulphate, which 
has already been explaiued on page 496 ; the next step is to make a 
solution of acid ammonium tartrate by neutralizing a solution ot 
14.5 Gm. of tartaric acid exactly with ammonia water and adding 
to this another like weight of tartaric acid. The well-washed ferric 
hydroxide is then added in successive portions to the solution of acid 
ammonium tartrate and dissolved with the aid of a moderate heat, 
after which the solution is treated as in the case of the other scale 
salts of iron. 

The reaction occurring may be illustrated by the following equa- 
tion : Fe 2 (OH) 6 +2JSrH^HC 4 H,0 6 =2NH,(FeO)C 4 H 4 6 +4H 2 0, in 
which the group FeO, to which the name ferry 1 has been given, acts 
as a univalent radical, like antimonyl. The scale compound, when 
carefully deprived of all water, probably has the composition ex- 
pressed by the formula, NH 4 (FeO)C 4 H 4 6 . 

Iron and ammonium tartrate is a deliquescent compound, requir- 
ing the careful exclusion of air and light. Like iron and ammonium 
citrate it is apt by age and exposure to become acid in character, and 
will then need the careful addition of a little ammonia water to re- 
store neutrality and effect solution. It contains a larger proportion 
of iron than any other official scale salt, the Pharmacopoeia requir- 
ing the equivalent of 17 per cent, of metallic iron. 

Iron and Potassium Tartrate. The official process for the 
preparation of this compound is very similar to that given for the 
preceding scale salt, except that acid potassium tartrate is used in 
place of acid ammonium tartrate. The hot solution of iron and 
potassium tartrate is not at once concentrated and spread on glass, 
but filtered and set aside for 24 hours to cool ; during this time a 
precipitate separates and the liquid becomes acid. Upon carefully 
neutralizing with ammonia water a perfect solution is again produced, 
which is then concentrated and scaled. 

Iron and potassium tartrate is recognized in the British Pharma- 
copoeia under the name Ferrum Tartaratum, and is so prescribed in 
Great Britain. It occasionally happens that, as in the case of the 
preced ing salt, it has become acid and difficultly soluble, probably owing 
to careless preservation ; in such a case a few drops of ammonia 
water carefully added to the residue will restore perfect solubility. 



THE COMPOUNDS OF IEOX. 501 

The theoretical composition of the salt when anhydrous is K(FeO) 
C 4 H 4 6 , based upon the equation, Fe 2 (OH) 6 + 2KHC 4 H 4 6 = 
2K(Fe0)C 4 H 4 6 -f 1H 2 0. Like all the other scale salts of iron, it con- 
tains variable proportions of water. The Pharmacopoeia requires the 
presence of an amount of iron in combination corresponding to 15 
per cent, of metallic iron. 

Iron and Quinine Citrate. The official scale compound of 
this name is unfamiliar to many pharmacists who have been in the 
habit of handling only the so-called soluble variety. It is prepared 
by dissolving 12 Gm. of dry quinine (pure alkaloid) in a strong solu- 
tion of 85 Gm. of ferric citrate, with the aid of 3 Gm. of citric acid, 
concentrating the solution on a water-bath to a syrupy consistence, 
and finally scaling the same on plates of glass. The yield is intended 
to be 100* Gm. 

The official iron and quinine citrate is intended chiefly to be used 
in the form of pills, tablets, etc., but not in solution ; for, although 
it is completely soluble in water, it dissolves very slowly. It is of a 
reddish-brown color, somewhat resembling ferric citrate in appear- 
ance, and deliquesces slowly in damp air. 

The Pharmacopoeia demands that the scale salt shall contain not 
less than 11.5 per cent, of dried quinine and an amount of iron cor- 
responding to 14.5 per cent, of that metal. Both can be determined 
in one sample, the quinine gravimetrically and the iron by the iodo- 
metric method, and thus much time and labor saved. The official 
estimation of the quinine is easily accomplished ; the addition of am- 
monia water to a solution of the salt precipitates the quinine as alka- 
loid, which, dissolving readily in the chloroform, can be withdrawn 
and the treatment with chloroform repeated twice, so as to insure the 
complete removal of the alkaloid. A globular separator (see Fig. 138, 
page 145) is better adapted for the operation than one of cylindrical 
shape, as, by simple rotation, the two liquids are brought into suffi- 
ciently intimate contact for abstraction of the alkaloid by the chloro- 
form, and separation takes place rapidly ; if shaking must be resorted 
to, it frequently happens that an emulsion results, which requires con- 
siderable time for separation. Owing to the low boiling-point of 
chloroform (60° C. (140° F.) ), the liquid should be evaporated with 
moderate heat only, so as to avoid loss by spurting, the residue being 
afterward dried at 100° C (212° F.) to constant weight. 

The residuary aqueous liquid retains all the ferric citrate, and, if 
25 Cc. of the same be used, after removal of all the chloroform and 
ammonia and dilution to 50 Cc, this will represent exactly one-half 
of the scale salt originally used, and therefore 14.5 Cc. of ^Na 2 S 2 3 
solution will be necessary to indicate 14.5 per cent, of metallic iron, 
1.12 Gm. having been used in the test. One-half of 1.12 is 0.56 and 
14.5 per cent, of 0.56 is 0.0812; hence, as each Cc. of >L Na 2 S 2 3 
solution represents 0.005588 Gm. of metallic iron, 14.5 Cc. will be 
equivalent to 0.081026 Gm. 



502 PHARMACEUTICAL CHEMISTRY. 

Soluble Iron and Quinine Citrate. As stated before, this 
is the salt generally dispensed by pharmacists, and is, in fact, the 
article usually sold by the jobber when citrate of iron and quinine is 
ordered. The Pharmacopoeia has added the adjective " soluble " to the 
title of this salt to distinguish it from the less soluble reddish-brown 
variety ; when the latter is wanted, pharmacists should always specify 
it by adding the letters U. S. P. to the name. 

Soluble iron and quinine citrate differs in composition from the 
preceding salt only in containing ammonia, which is combined with 
citric acid, wherebv the solubility of the compound is greatly in- 
creased, just as in the case of iron and ammonium citrate. The am- 
monia water is added to the solution of iron and quinine citrate first 
prepared as long as the precipitate formed is redissolved ; an excess 
of ammonia must be carefully avoided. The solution acquires a 
greenish-yellow color and yields greenish, golden-yellow scales, which 
readily absorb moisture upon exposure to the air and are rapidly sol- 
uble in cold water. 

The estimation of the iron and quinine is made exactly as in the 
plain iron and quinine citrate, the required proportion of each being 
identical in both salts. 

Iron and Strychnine Citrate. For the preparation of this 
compound the Pharmacopoeia directs the use of iron and ammonium 
citrate, in order to obtain at once a readily soluble product ; 1 Gm. 
each of strychnine and citric acid are dissolved in about 20 Cc. of 
water and added to a solution of 98 Gm. of iron and ammonium 
citrate in its own weight of water, the mixed liquids being concen- 
trated and scaled on glass like other scale salts. 

The Pharmacopoeia requires for this preparation the presence of 
not less than 0.9 nor more than 1 per cent, of strychnine and a pro- 
portion of ferric citrate corresponding to 16 per cent, of metallic iron. 
The assay is made in the same manner as prescribed for iron and 
quinine citrate. 

Solution of Ferric Acetate. An aqueous solution of ferric 
acetate, Fe 2 (C 2 H 3 2 ) 6 , containing about 31 per cent, of the anhydrous 
salt. The Pharmacopoeia directs that it be prepared by dissolving 
well- washed ferric hydroxide in glacial acetic acid, and since the 
presence of even traces of ammonium salts has been found to inter- 
fere with the stability of the solution, the precipitated hydroxide is 
directed to be washed with boiling water until a reaction for ammo- 
nium compounds can no longer be obtained in the washings. This 
is an important part of the process, as experiments made with this 
preparation a few years ago demonstrated the fact that a solution 
made with ferric hydroxide absolutely free from ammonium and 
other alkali compounds remained clear, even when exposed to the 
heat of a boiling-water bath for some time, while solutions prepared 
with imperfectly washed ferric hydroxide began to deposit basic ferric 
acetate, even at a moderate elevation of temperature in a short time. 



THE COMPOUNDS OF IE OX. 503 

The complete removal of ammonium sulphate from ferric hydroxide 
with cold water is not readily accomplished, and although the treat- 
ment with boiling water renders the precipitate more compact, chang- 
ing it to an oxy hydrate, there will be no difficulty in dissolving it 
iu the glacial acetic acid. 

The official solution of ferric acetate has a specific gravity of about 
1.16, at 15° C. (59° F.), and contains, in each Cc, very nearly 0.36 
Gm. of anhydrous ferric acetate, or about 161 grains in each fluid- 
ounce. The Pharmacopoeia requires the solution to contain the 
equivalent of 7.5 per cent, of metallic iron, which is determined by 
the iodometric method, after conversion of the ferric acetate into ferric 
chloride, by means of hydrochloric acid. 

Solution of Ferric Chloride. An aqueous solution of ferric 
chloride, Fe 2 Cl 6 , containing about 37.8 per cent, of the anhydrous 
salt. The preparation of this solution has already been fully ex- 
plained under Ferric Chloride (see page 494) ; the two preparations 
are made exactly alike, except that in the case of dry ferric chloride 
the solution is evaporated to a certain weight and allowed to crystal- 
lize, while in the case of the official solution it is brought up to a 
certain density, by the addition of water, if necessary. 

Solution of ferric chloride contains a small amount of free hydro- 
chloric acid, but should be absolutely free from ferrous salt and ferric 
oxy chloride, as well as nitric acid and other nitrogen compounds. 
Commercial solutions of ferric chloride are frequently contaminated 
with ferric oxychloride and nitrous odors are often perceptible. 

The official solution has a specific gravity of about 1.387, at 15° C. 
(59° F.), and contains nearly 0.524 Gm. of anhydrous ferric chloride 
in each Cc, or about 240 grains in each fluidounce; its chief use in 
pharmacy is for the preparation of the tincture of ferric chloride. 
The Pharmacopoeia requires that the solution shall contain an amount 
of ferric chloride corresponding to 13 per cent, of metallic iron, which 
is determined exactly as in the case of the dry salt. 

Solution of Ferric Citrate. An aqueous solution of ferric 
citrate containing about 32.85 per cent, of the anhydrous salt, 
Fe 2 (C 6 H 5 7 ) 2 , which corresponds to 7.5 per cent, of metallic iron, 
together with a slight excess of citric acid. This solution is prepared 
in a very similar manner to solution of ferric acetate, except that 
citric acid is used in place of glacial acetic acid and that the precipi- 
tate of ferric hvdroxide is washed with cold, instead of hot, water. 

The equation, 2(H 3 C 6 H 5 7 -f H 2 0) + Fe 2 (OH) 6 = Fe 2 (C 6 H,0 7 ) 2 + 
8H 2 0, shows that 419 parts of citric acid require 213.52 parts of 
ferric hydroxide to form 488.84 parts of the normal citrate. In the 
official formula for this solution, 1050 Gm. of solution of ferric 
sulphate are used, which theoretically will yield 161 .18 Gm. of ferric 
hydroxide, but there is always some loss in washing and transferring 
the precipitate, so that the amount of citric acid prescribed, 300 Gm., 



504 PHARMACEUTICAL CHEMISTRY. 

is usually in slight excess ; 300 Gm. of citric acid require 152.87 
Gm. of ferric hydroxide, and the amount of free acid in the finished 
solution will depend upon the care with which the loss of hydroxide 
is controlled. 

The official solution of ferric citrate has a specific gravity of about 
1.250, at 15° C. (59° F.). The amount of iron salt required by the 
Pharmacopoeia corresponds to 7.5 per cent, of metallic iron, which is 
determined as in the case of solution of ferric acetate. 

Solution of Ferric Nitrate. An aqueous solution of ferric 
nitrate, Fe 2 (N0 3 ) 6 , containing about 6.2 per cent, of the anhydrous 
salt. This is the weakest of the official simple iron solutions aud is 
prepared by dissolving freshly precipitated ferric hydroxide in nitric 
acid. 

The nitric acid used should be of full official strength, in order to 
produce a normal ferric nitrate, for which the prescribed quantity of 
acid is sufficient ; 180 Gm. of solution of ferric sulphate will yield 
27.63 Gm. of ferric hydroxide, which require 48.82 Gm. of absolute, 
or 71 Gm. of official, nitric acid, as shown by the equation, Fe 2 (OH) 6 
+ 6HN0 3 =Fe 2 (N0 3 ) 6 +6H 2 0. If a weaker acid be employed, basic 
ferric nitrates of deeper color will be produced. The Pharmacopoeia 
requires that the solution shall contain an amount of ferric nitrate 
corresponding to 1.4 per cent, of metallic iron, which is estimated as 
in the case of ferric acetate solution. 

Solution of ferric nitrate has a specific gravity of about 1.050 at 
15° C. (59° F.)and contains in each Cc. about 0.065 Gm., or in each 
fluidounce about 30 grains, of the anhydrous salt. 

Solution of Ferric Subsulphate. An aqueous solution of 
basic ferric sulphate of variable composition. It is prepared by 
adding 675 Gm. of ferrous sulphate to a heated mixture of 65 Gm. 
each of sulphuric and nitric acids and 500 Cc. of water ; when effer- 
vescence ceases, the liquid is tested for ferrous salt, and, if this be 
found present, nitric acid is added, drop by drop, to the hot liquid, 
as long as it causes further effervescence and the disengagement of 
red fumes. Finally the liquid is boiled until a clear ruby-red solution 
is obtained, entirely free from nitrous odor, and is diluted with water 
to the weight of 1000 Gm. 

The ferrous sulphate is used in the form of a coarse powder and 
added to the hot acid mixture in divided portions, in order to avoid 
a violent reaction. In the presence of nitric and sulphuric acids, 
oxidation takes place, converting the ferrous into a ferric salt, but, 
owing to an insufficient amount of sulphuric acid, a basic, instead of 
a normal, ferric sulphate is produced, the composition of which is 
variable, hence no definite formula can be assigned to it, although 
the following, Fe 4 0(S0 4 ) 5 , is used by some to illustrate the nature of 
the salt. In the preparation of this, as well as the next following 
solution, copious red vapors are evolved, due to the escape of nitric 



THE C03IP0UXDS OF II? OX. 505 

oxide into the air, and the liquid assumes a black tint temporarily, 
on account of a union between the ferrous sulphate and nitric oxide; 
these phenomena have already been explained in connection with the 
manufacture of ferric chloride. 

If a little sulphuric acid be added to solution of ferric subsulphate, 
the color becomes lighter, and, if added to the extent of one-half the 
volume of the latter, a white mass, consisting of anhydrous ferric 
sulphate, w T ill separate. 

The name Monsel's Solution is usually applied to this preparation, 
which is also prescribed by physicians as solution of persulphate ot 
iron ; although chemically incorrect, this last name is frequently em- 
ployed in this country, when the official solution of the subsulphate 
is intended, particularly by some of the older physicians. 

Solution of ferric subsulphate is a dense solution, having a specific 
gravity of about 1.550, at 15° C. (59° F.), and is apt to separate 
a semi -solid crystalline whitish mass upon standing, particularly in 
the cold. This is not a sign of deterioration, but is due to the con- 
centration of the solution, and can be overcome by placing the bottle 
in warm water for a while and agitating, when perfect solution will 
be restored. The Pharmacopoeia demands that the amount of basic 
ferric sulphate present in this solution shall correspond to 13.6 per 
cent, of metallic iron, to be estimated in the same manner as indicated 
for the other iron solutions. 

Solution of Feeeic Sulphate. An aqueous solution of nor- 
mal ferric sulphate, Fe 2 (S0 4 ) 3 , containing about 28.7 per cent, of 
the salt. This solution is not used medicinally, being only employed 
for the preparation of other iron compounds. It is made in the 
same manner as solution of ferric subsulphate, except that a larger 
proportion of acids is used, a different product being^ therefore, 
obtained. The following equation, 6(FeS0 4 - 7H,0) -3H,S0 4 + 
2HNO ? =3Fe 2 (S0 4 ) 3 + 2NO-|-46H 2 } shows that the reaction 
results in the formation of a normal salt, which is the only point of 
difference in the composition of this and the preceding solution. 

Solution of ferric sulphate is known in the British Pharmacopoeia 
as Solution of Persulphate of Iron, but the official Latin title of the 
United States Pharmacopoeia, Liquor Ferri Tersulphatis, is prefer- 
able, as at once indicating the true nature of the chemical compound 
present. It can be readily distinguished from MonsePs solution by 
a lower density and lighter color, and also by not separating white 
ferric sulphate upon addition of one-half its volume of sulphuric 
acid. The solution has a specific gravity of about 1.320, at 15° C. 
(59° F.), and is required to contain an amount of ferric sulphate cor- 
responding to 8 per cent, of metallic iron. 

Solution of Iron and Ammonium Acetate. This well-known 
preparation is usually prescribed by physicians as " Basham's Mix- 
ture," or under its old official (1880 Pharmacopoeia) title, Mistura 



506 PHARMACEUTICAL CHEMISTRY. 

Ferri et Arnmonii Acetatis. It is readily prepared by adding to 
200 Cc. of solution of ammonium acetate successively, 30 Cc. of 
diluted acetic acid, 20 Cc. of tincture of ferric chloride, 100 Cc. of 
aromatic elixir, 100 Cc. of glycerin, and sufficient water to bring the 
total volume up to 1000 Cc. 

As its name indicates, the solution contains both iron and ammo- 
nium acetates, the former salt, to which the deep red color of the 
liquid is due, being formed, at the time of preparation, by mutual 
decomposition between the ferric chloride and a part of the ammo- 
nium acetate ; a small amount of ammonium chloride is also formed. 
It is important that the solution of ammonium acetate be not alkaline, 
so that, upon addition of the diluted acetic acid, an excess of the 
latter shall be present, to avoid the formation of basic ferric acetate 
when the tincture of ferric chloride is added. 

Although the Pharmacopoeia directs that this preparation should 
be freshly made when wanted, this is not necessary, as, when pre- 
pared strictly according to the present official formula, it keeps well 
for months, without showing any signs of change, even in diffused 
light or during hot summer weather. The old formula of 1880 was 
defective, but the use of glycerin, in place of syrup, has completely 
remedied the evil. 

Tincture of Ferric Chloride. This is a hydro-alcoholic 
solution of ferric chloride, containing about 13.6 per cent, of the 
anhydrous salt. The Pharmacopoeia directs that 250 Cc. of solution 
of ferric chloride shall be mixed with sufficient alcohol to yield 1000 
Cc; this will require slightly more than 750 Cc. of alcohol, on ac- 
count of the contraction of volume which invariably results when 
aqueous liquids and alcohol are mixed. The official directions, to 
set the mixture aside for a period of three months, are for the pur- 
pose of allowing certain changes to take place before dispensing the 
tincture ; these changes are due to reaction between the acid solution 
of ferric chloride and alcohol, resulting in the formation of ethyl 
chloride and other ethereal products, which modify the odor of the 
preparation to some extent, and are said also to possess marked 
medicinal properties. By some authorities, it is claimed that these 
changes will not be completed at the end of three months, and that, 
in fact, they will continue for a period of six or nine months. 

Occasionally the mixture is found to deposit a yellowish-brown 
sediment ; this is due to ferric oxychloride, and is an evidence that 
the solution of ferric chloride used was deficient in hydrochloric acid, 
and, therefore, not properly made. 

Tincture of ferric chloride contains, in each Cc, about 0.130 Gm. 
of anhydrous, or 0.216 Gm. of official, ferric chloride, equivalent to 
about 60 and 100 grains respectively in each fluidounce. Upon ex- 
posure to sunlight, it is gradually changed in color, assuming a 
greenish-brown tint, owing to reduction of the ferric to ferrous salt, 
hence it should be protected from strong light. 



THE COMPOUNDS OF IB OX. 507 

The proportion of ferric chloride present in the official tincture 
corresponds to 4.7 per cent, of metallic iron and is determined, in 
the usual manner, with potassium iodide and sodium thiosulphate. 

Besides the official preparations of iron, the following are em- 
ployed : 

Albuminate of Iron. This compound occurs in the form of 
yellowish-brown scales, obtained by concentrating an alkaline solu- 
tion of ferric albuminate (see solution of albuminate of iron), w r ith 
the aid of a low heat, spreading the same on plates of glass and dry- 
ing at a moderate temperature. It represents between 3 and 4 per 
cent, of metallic iron and must be carefully preserved. 

Arsenate of Iron. This preparation, as found in the market, 
is of variable composition. It is recognized in the British Phar- 
macopoeia as arseniate of iron and directed to be made by mixing a 
solution of sodium arsenate with one of ferrous sulphate and addiug 
some sodium bicarbonate. Ferrous arsenate, Fe 3 As 2 8 , is precipi- 
tated, which is well washed and dried, in the meantime undergoing 
oxidation and changing from greenish-white to olive-green or bluish- 
green in color. 

Bexzoate of Iron. Ferric Benzoate, Fe 2 (C 7 H 5 2 ) 6 . This salt 
may be obtained as a pale-brownish powder by adding a concen- 
trated solution of sodium benzoate to a solution of ferric sulphate, 
washing the resulting precipitate with a little cold water and drying 
the same. 

Bromide of Iron. Ferrous Bromide, FeBr 2 . This compound is 
prepared by direct union of iron and bromine in the presence of 
water ; an excess of iron wire is used, and, when a pale-green solu- 
tion results, it is filtered and evaporated to dryness in a bright iron 
dish. It forms a dark, almost black mass, which turns brown 
through oxidation upon exposure to air, hence it must be preserved 
in tightly stoppered bottles. 

Dialyzed Iron. Under this name, a solution of a highly basic 
ferric oxychloride has been used by physicians for many years. It 
is recognized in the British and German Pharmacopoeias. The 
official German preparation is obtained by simply dissolving freshly 
prepared ferric hydroxide in water, with the aid of a very small 
quantity of hydrochloric acid and a gentle heat, but is not dialyzed 
subsequently. The British Pharmacopoeia directs a process which 
is about the same as that usually followed in this country, namely, a 
solution of ferric chloride is saturated with freshly made ferric hy- 
droxide, the liquid placed in a dialyzer (see page 152) and suspended 
in water, which is frequently renewed, as long as the latter shows 



508 PHARMACEUTICAL CHEMISTRY. 

any reaction for chlorides. Complete removal of ferric chloride is 
neither practicable nor desirable, and highly basic oxychlorides give no 
reaction with silver nitrate. The solution of ferric oxychloride re- 
maining in the dialyzer is then diluted with sufficient water so that 
100 parts by weight, when evaporated and dried at a temperature 
not above 100° C. (212° F.), shall yield 5 parts of solid residue. 
The composition of the ferric oxychloride found in commercial dia- 
lyzed iron varies, ranging between Fe 2 Cl 6 + 10F 2 O 3 , and Fe 2 Cl 6 + 
35Fe 2 O s ; still more highly basic oxychlorides can be obtained by 
dialysis, but the solutions are apt to gelatinize on standing. 

Ferrocyanide of Iron. Ferric Ferrocyanide, Fe 4 (Fe(CN) 6 ) 3 . 
When a solution of potassium ferrocyanide is gradually added to a 
dilute solution of ferric sulphate, a dark blue precipitate, having the 
above composition, is obtained. The precipitate must be well washed 
with boiling water to remove all potassium sulphate and is then dried. 

Iodide of Iron. Ferrous Iodide, Fel 2 . This preparation is 
obtained by first making a solution of ferrous iodide, as already 
explained in connection with saccharated iodide of iron, and evapo- 
rating this, in a bright iron dish, to dryness. It occurs as a very 
deliquescent black mass, which must be carefully preserved in tightly 
stoppered bottles. 

Malate of Iron. Impure ferrous malate occurs in the form of 
a blackish-green mass, obtained by digesting the juice of sour apples 
with iron filings, filtering and evaporating the solution to the con- 
sistence of an extract. It is recognized in the German Pharmaco- 
poeia under the name of Extractum Ferri Pomatum. 

Oxalate of Iron. Ferrous Oxalate, FeC 2 4 . This salt may 
be conveniently prepared by mixing a solution of acid ammonium 
oxalate with one of ferrous sulphate ; the lemon-yellow precipitate 
of ferrous oxalate is well washed with water until a reaction for sul- 
phuric acid is no longer obtained, and then dried. This process affords 
a better yield than if ferrous sulphate be treated with pure oxalic 
acid, since some of the salt would be lost by solution in the diluted 
sulphuric acid. 

Phosphate of Iron. This compound has already been mentioned 
in connection with the soluble salt of the same name. It is a variable 
mixture of ferrous and ferric phosphates with ferric oxide and is 
recognized in the British Pharmacopoeia, which directs it to be pre- 
pared by adding a solution of sodium phosphate to one of ferrous 
sulphate, finally adding some sodium bicarbonate. The precipitate 
of ferrous phosphate, Fe 3 (P0 4 ) 2 , is washed and dried, during which 
time it is slowly oxidized. Phosphate of iron is a slate-blue amor- 
phous powder, insoluble in water. 



THE COMPOUNDS OF IEOX. 509 

Peptonate of Iron. If egg-albumen be digested with pepsin 
and very dilute hydrochloric acid, for some time, at a temperature 
not exceeding 40° C. (104° F.), a solution of peptone will be obtained, 
which, after being neutralized with solution of soda and added to a 
solution of ferric oxychloride, yields a precipitate of ferric peptonate. 
In order to obtain the compound in soluble form the precipitate is 
dissolved in water, with the aid of a little hydrochloric acid and heat, 
the solution evaporated to a syrupy consistence and spread on plates 
of glass to be dried at a temperature not above 30° C. (86° F.). 

Saccharated Oxide of Iron. This preparation, known also 
as soluble oxide of iron, is officially recognized in the German Phar- 
macopoeia and used to some extent in this country. It is prepared 
by adding to freshly prepared ferric hydroxide a given proportion 
of sodium hydroxide solution and sugar, heating the mixture to per- 
fect solution, then evaporating to dryness, powdering and incorpor- 
ating with it sufficient sugar to bring the product up to a definite 
weight, representing the equivalent of 3 per cent, of metallic iron. 
The exact composition of the reddish-brown powder, is as yet not 
clearly understood ; it is considered to be a sodio-ferric saccharate, 
the presence of the alkali being essential, as, with sugar alone, ferric 
hydroxide does not form a perfectly soluble compound. 

Salicylate of Iron. Ferrous Salicylate. Fe(C 7 H 5 3 ) 2 . This 
is best prepared by dissolving freshly precipitated ferrous carbonate 
in water, by means of salicylic acid, with the aid of a gentle heat, 
filtering and evaporating the solution to dryness on a water-bath. 

Solution of Albuminate of Iron. An aromatic, alkaline solu- 
tion of ferric albuminate prepared, according to the German Phar- 
macopoeia, as follows : A solution of 35 parts of dry egg-albumen 
in 1000 parts of water is slowly added to a mixture of 120 parts of 
solution of oxychloride of iron and 1000 parts of water, the result- 
ing precipitate is well washed with water until all chlorine has been 
removed and then dissolved in 3 parts of solution of soda (sp. grav. 
1.17) diluted with 50 parts of water. To this solution are added 
150 parts of alcohol, 100 parts of cinnamon water, 2 parts of aro- 
matic tincture, and sufficient water to bring the total weight up to 
1000 parts. It represents about 0.4 per cent, of metallic iron. 

Subcarbonate of Iron. Under this name an amorphous red- 
dish-brown powder has long been known in pharmacy and was, at 
one time, recognized in the Pharmacopoeia (1870). It is a variable 
mixture, the composition depending upon age and the temperature at 
which it has been dried, and consists chiefly of ferric oxide and hy- 
droxide with some ferrous carbonate. The manner of preparing it 
is to mix solutions of ferrous sulphate and sodium carbonate together, 
whereby greenish-white ferrous carbonate is precipitated ; this is 



510 PHARMACEUTICAL CHEMISTRY. 

thoroughly washed with water and dried, during which operation it 
rapidly darkens and becomes oxidized with the elimination of carbon 
dioxide. Subcarbonate of iron is practically identical with ferric 
oxyhydrate Fe 2 3 -f Fe 2 (OH) 6 , and is often designated as red steel- 
dust by the public. 

Syrup of Arsenate of Iron. A preparation of the National 
Formulary containing about -gL- grain of ferric arsenate, Fe 2 As0 4 , in 
each fluidounce. It is made by preparing a solution of ferric arsen- 
ate from sodium arsenate and ferric citrate and mixing this with 
simple syrup, the ferric arsenate being held in solution by the newly 
formed sodium citrate. 

Syrup of Citro-iodide of Iron. This preparation also known 
as " tasteless syrup of iodide of iron " is made according to the 
National Formulary by dissolving iodine in a solution of ferrous 
iodide and adding this solution to a solution of potassium citrate; as 
soon as a deep-green color has developed, sugar is added and dissolved 
by agitation. Each fluidounce contains about 29 grains of ferric 
iodide, Fe 2 I 6 , equivalent to about 0.0685 Gm. in each Cc. 

Syrup of Soluble Oxide of Iron. This syrup may be con- 
veniently prepared extemporaneously as wanted, by forming a solu- 
tion of equal parts by weight of saccharated oxide of iron, water, 
and simple syrup. This is the formula given by the German Phar- 
macopoeia ; a more tedious process for making the syrup from solu- 
tion of ferric chloride is given in the National Formulary. Each 
fluidounce- of the syrup represents about 6 J grains of metallic iron 
or about 0.0143 Gm. in each Cc. 

Tincture of Citro-chloride of Iron. The National Form- 
ulary directs this preparation, which is better known as " tasteless 
tincture of iron," to be made by adding sodium citrate to a diluted 
solution of ferric chloride and heating until perfect solution is effected. 
Alcohol is then added and finally sufficient water to make up the re- 
quired volume. The tincture is of a deep-green color and the amount 
of iron represented is about the same as in the official tincture of 
ferric chloride. 



CHAPTER XLVIII. 

THE COMPOUNDS OF MANGANESE AND CHROMIUM. 

Of these two metals the Pharmacopoeia recognizes but three com- 
pounds, and even these are not frequently employed. The official 
preparations are as follows : 

Official English Name. Official Latin Name. 

Manganese Dioxide, ManganiDioxidum. 

Manganese Sulphate, Mangani Sulphas. 

Chromic Acid, Acidum Chromicum. 

Manganese Dioxide. Mn0 2 . The Pharmacopoeia recognizes 
native crude mauganese dioxide, commouly known as pyrolusite, 
which, while suitable for the manufacture of chlorine aud similar 
purposes, is frequently unfit for internal use, owing to the large pro- 
portion of foreign matters present. The quality of commercial man- 
ganese dioxide is, of course, very variable, some very rich specimens 
having occasionally been encountered. An artificial product occurs 
in the market, in the form of a very dark, almost black, tolerably fiue 
powder, which is far superior to the crude article, and should alone 
be used for dispensing purposes. It is possibly prepared by gentle 
ignition of manganese nitrate or by moderate heating of manganese 
hydroxide. 

The Pharmacopoeia admits manganese dioxide containing only 66 
per cent, of pure Mn0 2 , but the artificial article put on the market 
by manufacturing chemists is usually guaranteed to represent 90 per 
cent, and over. The valuation is made by means of treatment with 
ferrous sulphate and hydrochloric acid, whereby all ferrous salt is 
converted into ferric salt, according to the following equation — 
3Mn0 2 -T-12HCl-f6(FeS0 4 -7H 2 0)=2Fe 2 (S0 4 )3-Fe 2 Cl 6 -3MnC] 2 
-f 48H 2 — showing that each molecule (or 86.72 parts) of pure 
manganese dioxide is capable of oxidizing two molecules (or 554.84 
parts) of crystallized ferrous sulphate, or, in other words, 1 Gm. of 
MnO, will suffice for the complete oxidation of 6.398 Gm. of FeS0 4 
-7H 2 0. 

In the official test, 1 Gm. of the commercial article will convert 
the 4.22 Gm. of ferrous sulphate completely into ferric sulphate and 
chloride, so that the subsequent addition of potassium ferrieyanide no 
longer causes a blue coloration, onlv, if at least 66 per cent, of pure 
Mn0 2 be present, for 6Q per cent, of 1 is 0.66 and 1 : 0.66 : : 6.398 
: 4.22. 



512 PHARMACEUTICAL CHEMISTRY. 

Manganese Sulphate. Manganous Sulphate. MnS0 4 -f4H 2 0. 
This salt is obtained by heating a mixture of manganese dioxide and 
sulphuric acid to dull redness, in a crucible, for some time ; when 
cool, the mass is treated with water and filtered. The solution, if 
iron be present, is digested with manganous carbonate, filtered, con- 
centrated aud crystallized at a temperature not below 20° C. (6S° F.). 
If the solution be allowed to crystallize at a temperature approaching 
5° C. (41° F.), a salt will be obtained containing 7 molecules, or 
nearly 46 per cent, of water, while the official salt should contain 
only 4 molecules, or 32.29 per cent. 

Manganous sulphate is used for the preparation of other manganese 
salts by mutual decomposition, such as the carbonate, hypophosphite, 
and iodide, which are occasionally used in pharmacy. 

Chromic Acid. Chromic Trioxide. Cr0 3 . Although this com- 
pound is commercially designated as an acid, and is also recognized 
in the Pharmacopoeia by that name, it is, strictly speaking, simply an 
anhydride and the name chromic trioxide or anhydride appears more 
appropriate. 

It is prepared by adding sulphuric acid to a saturated solution ot 
potassium dichromate, when the following reaction occurs : K 2 Cr 2 7 
-f 2H 2 S0 4 = 2Cr0 3 +2KHSO 4 -f-H 2 O; the mixture becomes heated 
and, upon cooling, separates needle-shaped crystals of chromic an- 
hydride, which are drained and dried on porous tiles. In order to 
remove the sulphuric acid generally adhering to the crystals, these 
are washed with small quantities of strong nitric acid and finally 
heated, in a porcelain dish, on a sand-bath, until nitrous odors are no 
longer perceptible. 

The color of commercial chromic anhydride, is not uniform, de- 
pending upon the purity of the article ; a light scarlet-red color usu- 
ally indicates the presence of sulphuric acid, and such a product is, 
as a rule, very deliquescent. The Pharmacopoeia demands the entire 
absence of sulphuric acid ; such an article is of a deep purplish-red 
color and not very hygroscopic. Owing to its ready decomposition 
by organic substances, often with explosive violence, chromic anhy- 
dride should never be brought into contact with alcohol or glycerin, 
and should always be weighed on watch-glasses, never on paper; if 
its aqueous solution requires filtration, this must be done by means 
of asbestos or glass-wool. 



CHAPTEE XLIX. 

THE COMPOUNDS OF MERCURY. 

Next to the preparations of iron, those of mercury are the most 
important obtained from the heavy metals. Like the iron com- 
pounds, they are divided into two series, designated as mercurous and 
mercuric compounds respectively. In mercurous compounds, mer- 
cury appears univalent, while in mercuric compounds it acts like a 
bivalent element. The Pharmacopoeia recognizes metallic mercury 
and twenty preparations of it and its compounds, as shown by the 
following list : 

Official English Name. Official Latin Xame. 

Mercury, Hydrargyrum. 

Mercury with Chalk, Hydrargyrum cum Creta. 

Ammoniated Mercury, Hydrargyrum Ammoniatum. 

Mild Mercurous Chloride, Hydrargyri Chloridum Mite. 

Yellow Mercurous Iodide, Hydrargyri Iodidum Flavum. 

Corrosive Mercuric Chloride, Hydrargyri Chloridum Corrosivum. 

Mercuric Cyanide, Hydrargyri Cyanidum. 

Red Mercuric Iodide, Hydrargyri Iodidum Rubrum. 

Yellow Mercuric Oxide, Hydrargyri Oxidum Flavum. 

Red Mercuric Oxide, Hydrargyri Oxidum Rubrum. 

Yellow Mercuric Subsulphate, Hydrargyri Subsulphas Flavus. 

Mass of Mercury, Massa Hydrargyri. 

Mercurial Ointment, Unguentum Hydrargyri. 

Mercurial Plaster, Emplastrum Hydrargyri. 

Ointment of Ammoniated Mercury, Unguentum Hydrargyri Ammoniati. 

Ointment of Mercuric Nitrate, Unguentum Hydrargyri Nitratis. 

Ointment of Yellow Mercuric Oxide, Unguentum Hydrargyri Oxidi Flavi. 

Ointment of Red Mercuric Oxide, Unguentum Hydrargyri Oxidi Rubri. 

Mercuric Oleate, Oleatum Hydrargyri. 

Solution of Mercuric Nitrate, Liquor Hydrargyri Nitratis. 

Ammoniac Plaster with Mercury, Emplastrum Ammoniaci cum Hydrargyro. 

Mercury. Hg. ISTearly all the commercial mercury is obtained 
by roasting the ore known as cinnabar, crude native sulphide of mer- 
cury, the sulphur escaping as sulphur dioxide, while metallic mercury 
is condensed and collected in suitable apparatus. *As thus obtained, 
it is usually contaminated with lead, copper, and other metals, from 
which it is freed by treatment with diluted nitric acid ; it is finally 
washed with water and dried. On a small scale mercury may be 
conveniently purified by shaking with solution of ferric chloride and 
subsequently washing with water. For medicinal purposes, only pure 
redistilled mercury, which possesses a bright lustre, should be used ; 
if contaminated with dust and other mechanical impurities, mercury 
may be conveniently strained through a piece of close muslin or 

33 



514 



PHARMACEUTICAL CHEMISTRY. 



chamois skin. For weighing small quantities of mercury, it is most 
conveniently transferred from the stock bottle to the balance by means 
of a drop-tube or pipette, as, owing to its great cohesiveness, it cannot 
be readily poured from a bottle. 

Mercury with Chalk. Although not so much used as formerly, 
this preparation, also known as " Gray Powder/' is still a very im- 
portant one, as it represents mercury in a fine state of division in 
powder-form, and is frequently used in infantile disorders. The 
official method of preparation depends upon extinguishment of the 
mercury by means of succussion, 38 Gm. of mercury being shaken 
with 10 Gm. of clarified honey, for 6 hours or longer in a strong 
bottle ; this is best effected in a mechanical shaker, such as is shown 
in Fig. 279, which can be readily attached to a water motor connected 



Fig. 279. 




Mechanical shaker. 



with a hydrant. The mixture of mercury and honey is afterward 
added to a thick, creamy paste, made of 57 Gm. of prepared chalk 
and a sufficient quantity of water, the whole being triturated until a 
uniform mixture results, which is finally dried at the ordinary tem- 
perature, and should be reduced to powder without trituration. 

In this fine state of division, mercury is very prone to oxidation 
if exposed to air and light ; hence the powder should be kept well 
protected from both. While traces of mercurous oxide cannot be 
entirely avoided, the presence of mercuric oxide should be carefully 
guarded against, and any change in color from gray to pink or red- 
dish, indicating dangerous oxidation, would render the article unfit 
for use ; neither should mercury with chalk be dispensed if the color 
has turned very dark-gray or blackish, as this shows excessive mer- 
curous oxidation. In the official test, mercurous oxide is detected 
by precipitation, as calomel by hydrochloric acid, while the mercuric 
oxide is converted into mercuric chloride and is then precipitated, 
either as mercuric sulphide, by hydrogen sulphide, or as calomel 
(being afterward reduced to metallic mercury) by stannous chloride. 



THE COMPOUNDS OF MERCURY. 515 

Ammoniated Mercury. NH 2 HgCl. This compound, better 
known as white precipitate, is prepared by pouring a solution of mer- 
curic chloride slowly, with constant stirring, into ammonia water, 
when the following reaction occurs: HgCl, + 2NH 4 OH = NH 2 HgCl 
+ NH 4 C1 -f- 2H 2 0. The Pharmacopoeia directs a solution of 100 
Gm. of mercuric chloride in 2000 Cc. of distilled water, which, 
after nitration to remove any calomel present, is added to 150 
Cc. of 10 per cent, ammonia water ; both liquids are used cold, and 
the resulting precipitate is washed with 400 Cc. of cold water to 
which 20 Cc. of ammonia water have been added. Finally, the pre- 
cipitate is dried, in a dark place, at a temperature not exceeding 30° 
C. (86° F.). These specific directions are for the purpose of avoid- 
ing the formation of a basic yellow compound, XH 2 (Hg 2 0)Cl, which 
is apt to occur by exposure to light or heat, and even excessive 
washing with plain water. 

The constitution of ammoniated mercury may be explained in two 
different ways. The simplest view is to consider it as mercuric chlo- 
ride, in which an atom of chlorine has been replaced by the group 
XH 2 (or amide), and, in that case, the name mercuric chloramide will 
be appropriate ; the other view is that evidently taken by the Phar- 
macopoeia in applying the synonym mercuric ammonium chloride to 
the compound, according to which, it is looked upon as ammonium 
chloride in which two atoms of hydrogen have been replaced by an 
atom of bivalent mercury. 

Ammoniated mercury is also known as amido-chloride of mercury, 
and is sometimes prescribed by German physicians as hydrargyrum 
amidato-bichloratum. 

Mild Mercurous Chloride. Hg 2 Cl 2 . This well-known salt, 
commonly called calomel, is prepared by subliming a mixture of mer- 
curous sulphate and sodium chloride in proper proportions. In order 
to obtain the product in the form of a soft fine powder, the vapors 
are conducted into a spacious chamber, into which steam is introduced 
simultaneously ; the presence of aqueous vapor also frees the subli- 
mate from mercuric chloride, some of which is always formed, by 
solution in the condensed water. Thus obtained, the product is known 
as hydrosublimed calomel. When mercurous chloride is sublimed 
without steam it becomes necessary to reduce the crystalline sublimate 
to fine powder, and wash it thoroughly with water until the wash- 
ings are no longer affected by ammonia water or ammonium sulphide, 
showing the complete removal of mercuric chloride. 

The mercurous sulphate used in the above process is made by 
moistening mercuric sulphate with water, adding an equivalent 
amount of mercury (200 parts for 296 parts of mercuric sulphate), 
and triturating the mixture until all globules of mercury disappear. 
The reaction between mercurous sulphate and sodium chloride, when 
heated together, is shown by the following equation : Hir 9 S0 4 + 
2 XaCl = Hg 2 Cl 2 + Xa 2 S0 4 . 



516 PHARMACEUTICAL CHEMISTRY. 

The appearance of calomel depends largely upon the degree of 
mechanical division ; while usually white, the finer the powder the 
more yellowish the tint. When exposed to light it gradually under- 
goes decomposition and assumes a grayish color, mercuric chloride 
being formed, with the elimination of mercury. 

Calomel has sometimes been prescribed by continental physicians 
under the names "aquila alba" and "mercurius dulcis." 

Yellow Mercueous Iodide. Hg 2 T 2 . The official process for 
the preparation of mercurous iodide involves two distinct steps. 
First, mercurous nitrate is made by treating 50 Gm. of mercury with 
a mixture of 20 Cc. each of nitric acid and water, in a dark place, 
until reaction ceases and a little mercury remains undissolved; the 
salt separates in the form of crystals having the composition 
Hg 2 (K"0 3 ) 2 -|- 2H 2 0, which are drained and dried on paper in the 
dark. 40 Gm. of the crystallized mercurous nitrate are then dissolved 
in 1000 Cc. of distilled water acidulated with 10 Cc. of nitric acid, and 
to this solution is added, slowly and with constant stirring, a solu- 
tion of 24 Gm. of potassium iodide in 1000 Cc. of water, when the 
following reaction occurs : (Hg 2 (N0 3 ) 2 + 2H 2 0) + 2KI = Hg 2 I 2 + 
2KN0 3 -f- 2H 2 0. The precipitate is drained on a filter and washed, 
first with water to remove all potassium nitrate and free acid, and 
afterward with alcohol, until the washings cease to be affected by 
hydrogen sulphide, to free it from mercuric iodide ; lastly, it is dried 
in the dark, on paper, at a temperature not exceeding 40° C. (104° F.). 

The addition of nitric acid is made to prevent the formation of a 
basic compound, which might otherwise occur ; it is also important 
that the potassium iodide be added to the mercurous nitrate lest, by a 
reversal of the process, mercuric salt be formed, which enters into 
solution as potassium mercuric iodide, while mercury is precipitated, 
a reaction well known to occur between alkali iodides and mercurous 
iodide, and illustrated by the equation, Hg 2 T 2 -f 2KI = (Hgl 2 -|- 
2KI) + Hg. 

Mercurous iodide must be carefully protected from light, as it 
readily undergoes decomposition. The true color of the salt, when 
pure, is bright yellow, hence all preparations of a green, or greenish- 
yellow color, must be looked upon as impure, the latter colors being 
due to an admixture of metallic mercury, w T hich, in a finely divided 
state, is blue, and consequently causes a greenish mixture with the 
pure yellow salt. 

Much green iodide of mercury is still sold by manufacturers, hav- 
ing been recognized in the Pharmacopoeias of 1870 and 1880, but its 
production is due to a faulty process of preparation. When mercury 
and iodine, or mercury and mercuric iodide, are triturated together, 
yellow mercurous iodide is formed with variable proportions of mer- 
curic iodide, some of the mercury remaining uncombined in a finely 
divided form ; upon subsequent washing with alcohol, the mercuric 
iodide is removed, leaving the insoluble mercurous salt intimately 



THE COMPOUNDS OF MERCURY. 517 

mixed with finely divided mercury, and of a green color. Similar 
results are apt to occur if mercurous iodide be precipitated from a 
strong neutral solution of mercurous nitrate by means of potassium 
iodide, hence the Pharmacopoeia directs a dilute acid solution. 

Mercurous iodide has been associated with syrup of ferrous iodide 
in prescriptions, but such mixtures are incompatible, metallic mer- 
cury being deposited, a reaction similar to that explained above taking 
place, and mercuric iodide held in solution by the ferrous iodide. 

Corrosive Mercuric Chloride. HgCl 2 . This compound, 
more familiarly known as corrosive sublimate, is obtaiued by subli- 
mation of an intimate mixture of mercuric sulphate and sodium 
chloride, both in the form of powder. Mercuric chloride is formed 
as the result of mutual decomposition; thus, HgS0 4 -j- 2NaCl = 
HgCl 2 +Na 2 S0 4 . The heat necessary for the process is apt to de- 
compose some of the mercuric sulphate with the formation of mer- 
curous chloride, which is volatilized and sublimed aloug with the 
mercuric salt. The British Pharmacopoeia directs the addition of a 
small portion of mauganese dioxide to the mixture before subliming 
it, for the purpose of preventing the formation of mercurous salt. 

Commercial mercuric chloride occurs in heavy crystalline masses 
and is usually contaminated somewhat with calomel, hence perfectly 
clear solutions can rarely be obtained, even with distilled water. For 
dispensing purposes, only the chemically pure article, obtained by 
recrystallization should be used. 

Aqueous solutions of mercuric chloride, if exposed to light, gradu- 
ally undergo decomposition, liberating hydrochloric acid and deposit- 
ing calomel. The presence of ammonium chloride, however, prevents 
the change. 

The pharmacopceial test for the presence of arsenic in mercuric 
chloride, depends upon the solubility of arsenic sulphide in ammonia 
water and its subsequent precipitation by hydrochloric acid, mercuric 
sulphide being insoluble in ammonia water. 

Mercuric Cyanide. HgCN 2 . This salt may be prepared pure 
by dissolving mercuric oxide (preferably the yellow) in hydrocyanic 
acid, avoiding an excess of the oxide, which would form a basic com- 
pound ; a slight excess of the acid is not objectionable, as it will be 
dissipated on evaporation of the solution. Simple agitation suffices 
to effect solution, the liquid being then concentrated and set aside, in 
a dark, cool place, to crystallize. The resulting crystals must be 
both dried and preserved with exclusion of light, as the salt will 
otherwise darken rapidly. 

Mercuric cyanide is the only cyanide of the heavy metals com- 
pletely soluble in water ; its solution is colorless, without odor, and 
differs from a solution of mercuric chloride in not being precipitated 
by alkali hydroxides or carbonates, silver nitrate, and potassium 
iodide. It is a very poisonous compound, rarely used in medicine. 



518 PHARMACEUTICAL CHEMISTRY. 

Red Mercuric Iodide. Hgl 2 . This salt is prepared by mutual 
decomposition between mercuric chloride and potassium iodide, the 
official directions being to pour a solutiou of 40 Gm. of the former 
salt and a solution of 50 Gm. of the latter, simultaneously, into a 
large volume of water, with active stirring, when the following reac- 
tion occurs: HgCl 2 + 2KI = Hgl 2 + 2KC1. The official formula 
employs the two salts very nearly in the proportions indicated in the 
foregoing equation, which are 4 and 4.898 respectively ; an excess of 
either salt must be avoided, since loss by formation of a soluble com- 
pound would result, an excess of potassium iodide producing potas- 
sium mercuric iodide (HgI 2 -j-2KI) and an excess of mercuric chloride 
causing the formation of mercuric iodochloride (HgI 2 -j-2HgCl 2 or 
Hg 3 I 2 Cl 4 ). _ 

Mercuric iodide is dimorphous, occurring crystallized both in the 
form of scarlet-red quadratic octahedra and yellow rhombic prisms, 
but the Pharmacopoeia recognizes the salt only in the form of an 
amorphous scarlet-red powder, which is obtained by the official 
method of preparation. When exposed to light, mercuric iodide 
gradually becomes paler in color, and should therefore be preserved 
in dark bottles. It is soluble in solutions of metallic iodides and 
sodium thiosulphate, as w r ell as alcohol, olive oil, castor oil, chloro- 
form, glycerin, and glacial acetic acid, forming colorless solutions in 
each case. 

Yellow Mercuric Oxide. HgO. The official formula for the 
preparation of this compound directs that a strong solution of 100 
Gm. of mercuric chloride be poured slowly, with constant stirring, 
into a dilute solution of 40 Gm. of 90 per cent, sodium hydroxide ; 
amorphous mercuric oxide is precipitated while sodium chloride 
enters into solution. The mixture is allowed to stand, at a moderate 
temperature, for an hour, to facilitate complete decomposition, after 
which the liquid is decanted and the precipitate repeatedly washed 
until free from alkali, drained and dried on paper, in a dark place, 
at a temperature of 30° C. (86° P.). 

Mercuric salts do not form hydroxides when added to alkali 
hydroxides, but mercuric oxide is precipitated instead, as shown by 
the equation, HgCl 2 +2NaOH=HgO+ 2NaCl+H 2 0. It is impor- 
tant that the alkali be used in excess, otherwise a dark-colored oxy- 
chloride will be formed, hence the mercuric chloride solution is poured 
into the soda solution in the official process. From the above equa- 
tion, it will be seen that 1 molecule (or 270.54 parts) of mercuric 
chloride requires 2 molecules (or 79.92 parts) of sodium hydroxide 
for complete precipitation ; hence 100 Gm. HgCl 2 will require 29.5 
Gm. NaOH ; official soda containing 90 per cent, of NaOH, the 
necessary excess of alkali is assured in the formula of the Pharma- 
copoeia, as 90 per cent, of 40 Gm. is 36 Gm. It is essential that the 
soda used be free from carbonate, otherwise mercuric carbonate will 
be formed. Potassa may be used in place of soda, but ammonia is 



THE COMPOUNDS OF MERCURY. 519 

inadmissible, owing to the formation of ammoniated mercury. In 
order to insure a bright orange-yellow product, heat and light must 
be excluded during precipitation and drying; unless protected from 
light the color of the oxide gradually darkens on keeping, and, if 
exposed to direct sunlight, decomposition rapidly occurs. 

Yellow mercuric oxide, being in a very tine state of division, is 
more active and more sensitive than the red oxide ; it is chemically 
identical with the latter, but differs from it in the molecular arrange- 
ment of its particles, being devoid of all crystalline structure. When 
digested w T ith a solution of oxalic acid, yellow mercuric oxide forms 
white mercuric oxalate, while the red oxide remains unaffected. 

Red Meecueic Oxide. HgO. Although the name " red precipi- 
tate" is commonly applied to this compound, it is never obtained by 
precipitation but always by calcination. As a rule, mercuric nitrate is 
triturated with metallic mercury until the latter is extinguished; the 
mixture is then heated, in a porcelain dish, until yellowish or red- 
dish vapors cease to be evolved and mercuric oxide remains. The 
metallic mercury is oxidized at the expense of the nitric acid expelled 
from the mercuric nitrate, and the process may be illustrated by the 
following equation: 2Hg(X0 3 ) 2 + Hg 2 =4HgO-f 4K"0 2 . 

Red mercuric oxide occurs as a crystalline powder or in crystal- 
line scales of an orange-red color, and by trituration with alcohol is 
gradually converted into a yellowish-red powder. When exposed to 
light it darkens in color, but more slowly than the yellow oxide, and, 
unlike the latter, it is not affected by hot solution of oxalic acid. 

Yellow Meecueic Subsulphate. Hg(HgO) 2 S0 4 . A basic 
mercuric sulphate, prepared by pouring normal mercuric sulphate into 
boiling water, whereby the latter salt suffers decomposition. The 
official directions are to prepare normal mercuric sulphate by gently 
heating a mixture of mercury 100 Gm., sulphuric acid 30 Cc, nitric 
acid 25 Cc, and water 40 Cc, uutil reddish fumes are no longer 
evolved, during which operation the following reaction occurs : 
Hg 3 +3H 2 S0 4 +2HNO s =3HgS0 4 +4H 2 + 2NO. The resulting 
mixture is heated in a porcelain dish, on a sand-bath, until a dry 
white mass remains, which is powdered and added, in small quanti- 
ties at a time, to 2000 Cc of boiling water, after which the mixture 
is kept boiling for ten minutes. The liquid is decanted, the precipi- 
tate washed with warm w r ater, until free from acid, and then dried 
with a moderate heat. 

The addition of nitric acid is not essential, but facilitates the for- 
mation of mercuric sulphate at a lower temperature, cold and even 
moderately warm sulphuric acid having no effect on mercury, espe- 
cially in the presence of water. When normal mercuric sulphate is 
added to boiling water decomposition results, basic sulphate being 
precipitated, while acid sulphate remains in solution ; thus, 5HgS0 4 
+2H 2 0=Hg(HgO) 2 S0 4 -2HgH 2 (S0 4 ) 2 ; the yield depends upon 
the temperature and the volume of water used. 



520 PHARMACEUTICAL CHEMISTRY. 

Yellow mercuric subsulphate is commercially better known by the 
name [" turpeth mineral.' 7 It should be completely soluble in 10 
parts of hydrochloric acid, showing the absence of mercurous and 
lead salts. 

Solution of Mercuric Nitrate. An acid liquid containing 
about 60 per cent, of mercuric nitrate and about 1 1 per cent, of free 
nitric acid. This, the only fluid preparation of mercury officially 
recognized, is made by solution of 40 Gm. of mercuric oxide in a mix- 
ture of 45 Gm. of nitric acid and 15 Gm. of water. According to 
the equation, 3HgO+8HN0 3 =3Hg(N0 3 ) 2 +2NO+4H 2 0, 647.24 
parts of mercuric oxide require 503.12 parts of absolute nitric acid 
to form 970.74 parts of mercuric nitrate; hence 40 Gm. will require 
2S.32 Gm. of absolute, or 34.3 Gm. of official, nitric acid and will 
yield 59.99 Gm. of the salt. Moderate dilution of the acid with 
water is advantageous, facilitating the solution of the newly formed 
salt. 

This very corrosive preparation, rarely used and then only for 
external application, requires great care in handling. It is also 
known by the name acid nitrate of mercury and is the densest solu- 
tion of the Pharmacopoeia, having a specific gravity of 2.100, at 
15° C. (59° F.). 

Among the non-official compounds of mercury of interest to the 
pharmacist, the following may be mentioned : 

Mercuric Sulphate. HgS0 4 . This salt, which has already 
been mentioned in connection with mercurous and mercuric chloride 
and mercuric subsulphate, may be prepared either by the process 
mentioned under the latter salt or by heating mercury with sul- 
phuric acid and evaporating the mixture to dryness, when a crystal- 
line product will be obtained; water and sulphur dioxide are elimi- 
nated during the operation. 

Mercurous Tannate. This compound is prepared by triturat- 
ing freshly prepared and finely powdered mercurous nitrate with a 
mixture of tannin and water until a homogeneous smooth mass is 
obtained. The mass is mixed with a large volume of water, and the 
green precipitate is washed with water until no trace of nitric acid 
remains, after which it is dried on porous tiles, at a temperature not 
exceeding 40° C. (104° F.). 

Mercuric Carbolate or Phenate. Of the two preparations 
occurring under this name, the so-called normal mercuric phenate, or 
mercuric diphenate, Hg(C 6 H 5 0) 2 , should be dispensed, being a stable 
preparation. It is obtained by mixing, with constant stirring, an 
alcoholic solution of mercuric chloride with an alcoholic solution of 
carbolic acid and potassium hydroxide, draining the yellowish-colored 



THE COMPOUNDS OF MERCURY. 521 

precipitate, washing it with hot water acidulated with acetic acid and 
recrystallizing from hot alcohol. 

Mekcumc Salicylate. HgOC 7 H 4 2 . This salt may be pre- 
pared by adding salicylic acid to freshly precipitated mercuric oxide 
rubbed into a smooth paste with water and heating the mixture on a 
water-bath until a snow-white mass remains, free from a yellow tint, 
which is then washed with warm water to remove excess of acid, 
drained and dried. The resulting amorphous product constitutes 
secondary or basic mercuric salicylate, which is the salt generally 
employed. Normal mercuric salicylate, Hg(C 7 H 5 3 ) 2 , can be obtained 
by precipitating a solution of mercuric chloride with sodium salicylate 
in the cold ; the resulting product is readily decomposed by heat. 



OHAPTEE L. 

THE COMPOUNDS OF ANTIMONY, ARSENIC, AND BISMUTH. 

While, at one time, the preparations of antimony formed an im- 
portant part of the physician's armamentarium, they are but rarely 
prescribed at the present time ; those of arsenic and bismuth, how- 
ever, are still looked upon as valuable remedial agents. The 
Pharmacopoeia recognizes five chemical compounds and three phar- 
maceutical preparations of antimony, two compounds of arsenic, 
besides four arsenical solutions and four compounds of bismuth, as 
shown by the following list : 

Official English Name. Official Latin Name. 

Antimony and Potassium Tartrate, Antimonii et Potassii Tartras. 

Antimony Oxide, Antimonii Oxidum. 

Antimony Sulphide, Antimonii Sulphidum. 

Purified Antimony Sulphide, Antimonii Sulphidum Purificatum. 

Sulphurated Antimony, Antimonium Sulphuratum. 

Compound Pills of Antimony, Pilulse Antimonii Compositse. 

Antimonial Powder, Pulvis Antimonialis. 

Wine of Antimony, Vinum Antimonii. 

Arsenic Iodide, Arseni Iodidum. 

Arsenous Acid, Acidum Arsenosum. 

Solution of Arsenous Acid, Liquor Acidi Arsenosi. 

Solution of Arsenic and Mercuric Iodide, Liquor Arseni et Hydrargyri Iodidi . 

Solution of Potassium Arsenite, Liquor Potassii Arsenitis. 

Solution of Sodium Arsenate, Liquor Sodii Arsenatis. 

Bismuth Citrate, Bismuthi Citras. 

Bismuth and Ammonium Citrate, Bismuthi et Ammonii Citras. 

Bismuth Subcarbonate, Bismuthi Subcarbonas. 

Bismuth Subnitrate, Bismuthi Subnitras. 

The Compounds of Antimony. 

Antimony and Potassium T arte ate. 2K(SbO)C 4 H 4 6 + 
H 2 0. This salt, which has been known for over 250 years, is pre- 
pared by boiling a mixture of acid potassium tartrate and antimonous 
oxide with water for some time, filtering the liquid, concentrating by 
evaporation and crystallizing. The British Pharmacopoeia directs 
that a paste be made of the antimonous oxide, cream of tartar, and a 
small quantity of water, which is set aside for twenty-four hours to 
allow combination to take place, after which more water is added and 
the mixture boiled for fifteen minutes to bring all the newly formed 
double tartrate into solution. 

If pure materials be used, the full theoretical yield is generally 
obtained, but, if the antimonous oxide be contaminated with oxy- 
chloride, some of the salt will be lost by refusing to crystallize in 



THE COMPOUNDS OF ANTIMONY. 523 

the acid liquid. The following equation, Sb 2 O s + 2KHC 4 H 4 6 = 
2K(SbO)C 4 H 4 6 -f- H 2 0, explains the formation of antimony and 
potassium tartrate, the univalent group SbO replacing the hydrogen 
in the acid potassium tartrate, water being formed at the same time. 

The synonyms, tartar emetic and tartrated antimony, are given in 
the Pharmacopoeia for this compound, the former being the name 
generally employed in commerce. The salt is recognized in the 
British Pharmacopoeia as antimonium tartaratum and in the German 
Pharmacopoeia as tartarus stibiatus. It is generally sold in powder 
form, obtained by trituration of the crystals. Aqueous solutions of 
tartar emetic gradually develop fungi, and, on that account, cannot 
be kept on hand for any length of time, nor can they be mixed with 
strongly alcoholic liquids without precipitation, as the salt is totally 
insoluble in alcohol. 

The Pharmacopoeia requires absolute purity for tartar emetic, the 
valuation being made with decinormal iodine solution in the presence 
of sodium bicarbonate and starch solution. The iodine, acting as an 
oxidizing agent, converts the antimony! into meta-antimonic acid, 
hydriodic acid and sodio-potassium tartrate being also formed ; the 
object of adding sodium bicarbonate is to neutralize the two newly 
formed acids, thereby preventing decomposition of the hydriodic 
acid by the meta-antimonic acid, which would liberate iodine and thus 
vitiate the end-reaction. The equation, (2K(SbO)C 4 H 4 6 -f H 2 0)-f- 
I 4 + 8NaHC0 3 = 2NaSb0 3 -f 4FaI + 2KNaC 4 H,0 6 + 8C0 2 + 
6H 2 0, shows that each molecule (or 662.42 parts) of crystallized 
tartar emetic requires 4 atoms (or 506.12 parts) of iodine for com- 
plete oxidation of the antimony present, hence 0.331 Gm. will require 
0.25306 Gm. of iodine or 20 Cc. of its decinormal solution, for 
662.42 : 506.12 : : 0.331 : 0.25306 and 0.25306 -f- 0.012653 = 20. 

In the official test for the presence of arsenic the addition of tin- 
foil should be omitted, as otherwise metallic autimouy will be pre- 
cipitated in a finely divided form, thus vitiating the reliability of the 
test, which depends upon the separation of metallic arsenic by the 
stannous chloride. 

Antimony Oxide. Antimonous Oxide. Antimony Trioxide. 
Sb 2 3 . This compound is obtained by first preparing a solution of 
antimony trichloride, SbCl 3 , from antimonous sulphide and hydro- 
chloric acid, pouring this into water, whereby antimony oxychloride, 
2SbCl 3 -{- 5Sb 2 3 (known as powder of Algaroth), is precipitated, 
which is then repeatedly washed with water and mixed with a solu- 
tion of sodium carbonate, converting the oxychloride into pure oxide, 
with elimination of carbon dioxide aud formation of sodium chloride, 
thus, (2SbCl 3 + 5Sb 2 3 ) + 3Na 2 C0 3 = 6Sb 2 3 + 6NaCl + 3C0 2 . 
In place of sodium carbonate, ammonia water is frequently em- 
ployed. After proper washing of the oxide, it is dried at a tem- 
perature not exceeding 100° C. (212° F.), so as to avoid the formation 
of higher oxides. v 



524 PHARMACEUTICAL CHEMISTRY. 

Antimony oxide is used in the manufacture of tartar emetic and 
antimonial powder. 

Antimony Sulphide. Sb 2 S 3 . Under this name the Pharma- 
copoeia recognizes native antimony sulphide, obtained from the ore 
stibnite, by fusion, whereby it is freed from accompanying infusible 
sulphides, siliceous matter, etc. It is the source of the other anti- 
mony compounds, and is known in commerce as black or crude 
antimony, occurring both in cone-shaped masses and powder-form of 
a steel-gray color, and having a metallic lustre. It is contaminated 
with variable proportions of arsenic trisulphide. 

Purified Antimony Sulphide. Sb 2 S 3 . In the official process 
for the purification of antimony sulphide, only the finely divided 
article, obtained by elutriation, is used, which is macerated for five 
days, in a closed vessel, with diluted ammonia water, with frequent 
agitation ; the liquid is then decanted and the residue repeatedly 
washed with water and dried at a gentle heat. Antimonous sulphide 
is always associated with arsenous sulphide, which it is intended to 
remove by the treatment with ammonia water, wherein it is soluble. 
Hager and others suggest that ammonium carbonate be added to the 
mixture, after two or three days' maceration, with a view of dis- 
solving less of the antimonous sulphide, which, although soluble to 
some extent in the ammonia water, is totally insoluble in solution of 
ammonium carbonate. 

Purified antimony sulphide differs in appearance from the crude 
sulphide, being a lustreless powder of dark-gray or grayish-black 
color. 

In the official test for the absence of more than -^ per cent, ot 
arsenic, all antimonous and arsenous sulphide present in the sample 
is oxidized by cautious ignition with sodium nitrate, sodium nieta- 
antimonate, NaSb0 3 , and sodium pyro-arsenate, Na 4 As 2 7 being 
formed. Upon addition of water, the latter salt is changed into 
sodium ortho-arsenate, Ka 2 HAs0 4 , and readily dissolves; the former 
salt is insoluble in cold and only slowly soluble in boiling water. 
The filtrate, containing all sodium arsenate, is boiled with nitric 
acid to convert the sodium nitrite (due to reduction of the sodium 
nitrate in the previous operation) into sodium nitrate, after which 
silver nitrate is added, whereby silver arsenate, Ag 3 As0 4 , is formed 
by double decomposition. Upon carefully pouring a little ammonia 
water on top of the solution, so as to form a neutral liquid at the 
line of contact, a white cloud will be observed if only a very minute 
quantity of arsenic was present in the sample of antimony sulphide, 
but, if more than -^ per cent, was present, the silver arsenate will 
separate as a flesh-colored or reddish-brown precipitate. Silver 
arsenate is soluble both in nitric acid and ammonia water, but is 
insoluble in neutral liquids, hence the separation will appear only at 
the line of contact. 



THE COMPOUNDS OF ARSEXIC. 525 

Sulphurated Antimony. This preparation consists chiefly of 
precipitated antimonous sulphide mixed with small and variable 
quantities of antimonous oxide. The Pharmacopoeia directs that 
purified native antimony sulphide be boiled with about twelve times 
its weight of a 5 per cent, solution of sodium hydroxide, for two 
hours, the liquid to be immediately strained, after which diluted sul- 
phuric acid is added, drop by drop, as long as it causes precipitation. 
The precipitate is washed with hot water to remove all sulphates, 
and then dried at a temperature not exceeding 25° C. (77° F.). 

Crystalline antimony sulphide is not affected by cold alkaline 
liquids, but, upon boiliug such a mixture, a solution is formed of 
alkali meta-autimonite and sulpho-antiraouite, as shown by the fol- 
lowing equation : Sb ? S 3 + 4NaOH = NaSb0 2 + ISTa 3 SbS 3 + 2H 2 0. 
This solution, which is colorless, is separated by straining, and, upon 
the addition of sulphuric acid, is decomposed, amorphous antimonous 
sulphide being precipitated, thus : NaSb0 2 -f- Na 3 SbS 3 -|- 2H 2 S0 4 = 
Sb 2 S 3 -f- 2Na 2 S0 4 -f- 2H 2 0. Small quantities of antimonous oxide 
are also formed and remain mixed with the sulphide. While the 
precipitated antimonous sulphide occurs as a reddish-brown amor- 
phous powder, it does not differ in its chemical composition from the 
black native sulphide, which is crystalline. 

The name Kermes Mineral is also officially applied to this prep- 
aration, which is not identical with the commercial Golden Sulphur 
of Antimony, recognized, in the British Pharmacopoeia, under the 
title of sulphurated antimony. To the latter preparation the German 
Pharmacopoeia applies the name stibium sulphuratum aurantiacum; 
it consists chiefly of antimony pentasulphide, Sb 2 S 5 , with possible 
admixtures of antimony trisulphide and oxide. Golden sulphur of 
antimony is of an orange-red color and is prepared in a similar man- 
ner to Kermes Mineral, except that sulphur is added to the mixture 
of black antimony sulphide and solution of soda. Upon boiling this 
mixture, sodium sulphide, Na 2 S, is formed, which, reacting with sul- 
phur and antimonous sulphide, yields sodium sulpho-antimonate, a 
compound known as Schlippe's salt, thus : Sb 2 S 3 -f- 3Na 2 S -J- S 2 = 
2Xa 3 SbS 4 ; this is decomposed by the addition of diluted sulphuric 
acid to its solution, when antimony pentasulphide is precipitated, 
hydrogen sulphide escaping and sodium sulphate remaining in solu- 
tion, thus : 2Na 3 SbS 4 + 3H 2 S0 4 =Sb 2 S 5 + 3H 2 S-j-3Na 2 S0 4 . Any 
admixture of antimony trisulphide is due to the possible formation 
of sodium sulpho-antimonite, Na 3 SbS 3 , during the boiling of the 
alkaline liquid, and its subsequent decomposition by the acid. 

The Compounds of Arsenic. 

Arsenic Iodide. AsI 3 . Arsenic is capable of forming several 
compounds w T ith iodine, of which, the one indicated by the above 
formula and more particularly known as arsenic triiodide, is alone 
recognized in the Pharmacopoeia. It may be obtained by fusing, in 



526 PHARMACEUTICAL CHEMISTRY. 

a loosely stoppered test-tube or bottle, a mixture of 4 Gm. of metallic 
arsenic aucl 10 Gm. of iodine and pouring the melted mass on a por- 
celain slab to cool. Some manufacturers prefer to make it by adding 
finely powdered metallic arsenic to a solution of iodine in carbon di- 
sulphide, until all color of iodine has disappeared, then concentrating 
and crystallizing the solution. 

Arsenic iodide must be carefully protected from air and light, 
otherwise it undergoes decomposition, lo§ing iodine and becoming in- 
soluble in water. Its aqueous solution gradually changes, arsenous 
and hydriodic acids being formed. The chief use made of the com- 
pound is in the preparation of Donovan's Solution. 

Aesenous Acid. As 2 3 . This compound has been known for 
centuries, and, although it is still designated as an acid by the Phar- 
macopoeia, the names, arsenic trioxide, arsenous oxide, or arsenous 
anhydride, seem more in conformity with its true character, since the 
dry substance evinces no acid properties whatever, and, even dissolved 
in water, shows only a very feeble acid reaction. It is obtained 
chiefly as a by-product in the roasting of tin, cobalt, and nickel ores, 
and is subsequently purified by sublimation. 

Arsenic trioxide occurs in two distinct varieties, an amorphous, 
vitreous (glass-like) form and a crystalline, opaque, porcelain-like 
variety, the former being gradually converted into the latter upon 
exposure to moist air. The solubility of the two varieties in water 
differs materially, the vitreous being nearly three times as soluble 
as the porcelain-like variety, but the solubility of both is increased 
by the presence of hydrochloric acid or alkali hydroxides and car- 
bonates, alkali arsenites being formed in the last two cases. When 
arsenic trioxide is dissolved in water, arsenous acid is formed, thus : 
As 2 3 -|-3H 2 = 2H 3 As0 3 , which, how T ever, cannot be isolated, as 
upon evaporation of the solution arsenic trioxide is again obtained. 
While alcohol exerts but a slight solvent effect on either variety, 
glycerin will dissolve about one-fifth of its weight of both, again de- 
positing a portion however upon dilution with water, and oil of tur- 
pentine dissolves the vitreous, but not the opaque variety. 

Although the synonym, ivhite arsenic, is officially recognized, it 
should be borne in mind that the commercial product in powder 
form, known as white arsenic, is usually impure and unfit for phar- 
maceutical purposes. Arsenic trioxide should never be purchased in 
powder form, except in bottles bearing on the label the name of some 
reputable manufacturer or dealer. 

The quality of arsenic trioxide can be readily ascertained by titra- 
tion with decinormal iodine solution, which converts arsenous into 
arsenic acid. The Pharmacopoeia requires that official arsenous acid 
shall contain not less than 98.8 per cent, of As 2 O s ; 0.1 Gm. dis- 
solved in 20 Cc. of water together with 1.0 Gm. of sodium bicar- 
bonate should decolorize at least 20 Cc. ^ I solution, the following 



THE COMPOUNDS OF ARSENIC. 527 

reaction taking place: As 2 3 -f- 8NaHC0 3 +I 4 +2H 2 0=2Na 2 HAs0 4 
+4NaI + 8C0 2 +5H 2 0. Since one molecule (or 197.68 parts) of 
arsenic trioxide requires 4 atoms (or 506.12 parts) of iodine for com- 
plete oxidation, each Cc. of ^ I solution must correspond to 0.004942 
Gm. As 2 3 and 20 Cc. equal 0.098848 Gm., which is 98.8 percent, 
of 0.1 Gm. The addition of sodium bicarbonate is made for the 
purpose of neutralizing the acids formed, thus preventing the con- 
stant liberation of iodine through decomposition of the hydriodic 
acid by the arsenic acid: 

Solution of Arsenous Acid. This is simply a solution of 
arsenous acid in water, containing also 5 per cent, of official diluted 
hydrochloric acid, which latter is added solely to facilitate solution 
of the arsenous oxide, no chemical action taking- place. Formerly 
this preparation was called solution of chloride of arsenic, under a 
false impression ; arsenous chloride, As 2 Cl 6 , can be obtained by 
treating arsenic trioxide with strong hydrochloric acid or by dis- 
tilling arsenous and hydrochloric acids together ; but, upon being 
dissolved in water, it is again split up into the compounds from which 
it was made. 

The Pharmacopoeia requires that the solution shall contain, in 
every Cc, 0.010 Gm. of official arsenous acid (corresponding to 
about 4.86 grains in every fluidonnce), which is determined by titra- 
tion with decinormal iodine solution, as in the case of the valuation 
of arsenic trioxide. 24.7 Cc. of the official solution, containing 
0.244 Gm. of absolute As 2 3 (1 Gm. of 98.8 per cent, arsenic tri- 
oxide in 100 Cc.) will require not less than 49.5 Cc. ^ I solution, 
each Cc. of which corresponds to 0.004942 Gm. As 2 3 , for com- 
plete oxidization. The reaction has been fully explained in the pre- 
ceding article. 

Solution of Arsenic and Mercuric Iodide. Ked mercuric 
iodide, which alone is almost insoluble in w T ater, becomes soluble in 
the presence of arsenic iodide, and, in preparing the above solution, 
the two iodides are triturated together and then mixed with water, 
when solution readily takes place. It is important that the arsenic 
iodide be of good quality, otherwise an insoluble residue will remain. 
The solution contains, in every Cc, 0.010 Gm. each of arsenic and 
mercuric iodide (corresponding to about 4.86 grains of each in every 
fluidounce), and should be preserved in small, well-stoppered vials, 
in a dark place, as it is prone to decomposition. When freshly 
made it is of a pale-straw color, and, if this changes to reddish or 
red, iodine has been liberated, and the solution should not be dis- 
pensed. 

This preparation is better known as Donovan's Solution, and was 
at one time considered a very valuable remedial agent, but is little 
used at present. On account of the powerful action of arsenic and 



528 PHARMACEUTICAL CHEMISTRY. 

mercuric iodides this solution was formerly called by some physicians 
The Three Samsons of Medicine. 

Solution of Potassium Arsenite. This preparation, popu- 
larly known as Fowler's Solution, is probably the most extensively 
employed of all arsenical compounds. It is made by heating arsenic 
trioxide and potassium bicarbonate with a small quantity of water 
until perfect solution has been effected, which when cold is diluted 
with water, and compound tincture of lavender added. The use of 
a small quantity of water is favorable to chemical union between 
the alkali and feeble acid ; the nature of the compound depends upon 
the proportions used; thus, in the formula of the United States 
Pharmacopoeia, one part of arsenic trioxide and two parts of potas- 
sium bicarbonate will produce the following reaction : 4KHC0 3 + 
As 2 3 + 3H 2 = 2K 2 HAs0 3 + 4H 2 0+4C0 2 , monobasic potassium 
ortho-arsenite being formed, while the preparations of the British and 
German Pharmacopoeias, made with equal weights of arsenic trioxide 
and potassium carbonate, contain potassium meta-arsenite, as shown 
by the equation, As 2 3 + K 2 C0 3 =2KAs0 2 + C0 2 . 

The solution is most conveniently prepared in a test-tube of suffi- 
cient capacity or a small long-neck flask, whereby the evaporation of 
water is materially reduced ; the dilution should not be made until 
the liquid is cold. Solution of potassium arsenite is apt to develop 
fungi in the course of time, and if an excess of alkali be present, as 
iu the British and German preparations, the arseuous acid is gradu- 
ally converted into arsenic acid ; it is, therefore, better not to keep 
the solution on hand in large quantities. While the preparations of 
the United States and British Pharmacopoeias are colored reddish by 
the compound tincture of lavender added, those of the German and 
French Pharmacopoeias are colorless. The term liquor arsenicalis is 
officially used in Great Britain to designate this solution. 

Owing to its very poisonous nature, Fowler's Solution should never 
be dispensed without a physician's prescription, and, although some- 
times called for by the public, pharmacists should refuse to sell it, for 
their own protection as well as that of others. 

The official solution of potassium arsenite must contain 1 Gm. of 
official arseuous acid in every 100 Cc. of solution, corresponding 
to 4.86 grains in each fluidounce, which is determined with iodine, 
exactly as in the case of solution of arseuous acid. 

Solution of Sodium Arsenate. An aqueous solution of so- 
dium arsenate, containing 0.010 Gm. of anhydrous salt in each Cc. 
The object of using anhydrous sodium arsenate is to insure uniformity 
of strength in the finished product, as the commercial salt contains 
variable proportions of water of crystallization (see page 443) ; the 
temperature used for desiccation should not be carried beyond 149° 
C. (300° F.), in order to avoid changing the sodium ortho-arsenate 
into pyro-arsenate. 



THE COMPOUNDS OF BISMUTH. 529 

This preparation is not identical with Pearson's Arsenical Solution, 
recognized in the French Pharmacopoeia, and prepared by dissolving 
1 part of crystallized sodium arsenate in 600 parts of water. As 
Pearson's Solution is sometimes prescribed in this country, it should 
be borne in mind that the solution of sodium arsenate of the United 
States Pharmacopoeia is about ten times as strong as the French 
preparation bearing Dr. Pearson's name. 



The Compounds of Bismuth. 

Bismuth Citrate. BiC 6 H 5 O r This salt is prepared by boiling 
a mixture of 100 Gm. of bismuth subnitrate and 70 Gm. of citric 
acid, with 400 Cc. of Avater, until a drop of the mixture forms a 
clear solution with ammonia water, after which it is diluted with a 
large volume of water, allowed to subside, and repeatedly washed 
with water by decantation, until free from nitric acid, and dried with 
the aid of a gentle heat. 

The use of a small quantity of water is advantageous for the com- 
plete conversion of the bismuth subnitrate into citrate ; the reaction 
taking place may be illustrated by the following equation : (BiON0 3 -{- 
H 2 0) + (H 3 C 6 H 5 7 + H 2 0) = BiC 6 H 5 7 + HN0 3 + 3H 2 0, which 
shows that 100 Gm. of bismuth subnitrate require 68.75 Gm. of 
crystallized citric acid (for 304.71 : 209.5 : : 100 : 68.75), which leaves 
a very slight excess of citric acid in the official formula. The com- 
position of bismuth subnitrate may differ, however, from the formula 
assigned to it in this reaction (see Bismuth Subnitrate). 

The only use made of the normal bismuth citrate in pharmacy is 
in the manufacture of the soluble compound next mentioned. 

Bismuth and Ammonium Citrate. The official formula for this 
preparation directs that ammonia water shall be gradually added to a 
smooth paste made of normal bismuth citrate and twice its weight of 
water, until a perfect solution has been effected, which is strained, 
concentrated on a water-bath to a syrupy consistency, and spread 
upon plates of glass to dry. A slight excess of ammonia water will 
be advantageous, in order to maintain a neutral or faintly alkaline 
reaction during evaporation of the solution, as some ammonia will be 
lost and an acid condition would cause precipitation. 

The exact composition of this compound cannot be definitely 
stated. By some, the view is held that, by the action of ammonia, 
bismuthous hydroxide is formed, which is held in solution by the 
ammonium citrate simultaneously produced, giving the salt the com- 
position indicated by the formula, Bi(OH) 3 -f (NH 4 ) 3 C 6 H 5 7 + Aq. ; 
others have suggested that the composition may be expresed thus : 
BiC 6 H 5 7 + JS T H 4 OH + H 2 0. 

The scaled salt obtained by the official process slowly loses am- 
monia, unless preserved in tightly stoppered bottles, thereby becom- 

34 



530 PHARMACEUTICAL CHEMISTRY. 

ing opaque and partly insoluble in water. When such a condition 
exists, the cautious addition of a few drops of ammonia water to the 
turbid mixture usually effects a perfect solution, as in similar cases 
of the iron scale-salts. 

The British Pharmacopoeia recognizes a solution of bismuth and 
ammonium citrate, which is prepared by dissolving 40 grains of 
normal bismuth citrate in one fluidounce of water by means of am- 
monia. It is prepared as described above, and is known in England 
also as liquor bismuthi. 

Bismuth Subcarbonate. The first step necessary in the manu- 
facture of this compound is the preparation of a solution of pure 
normal bismuth nitrate, which is then decomposed by meaus of a cold 
solution of sodium carbonate. When metallic bismuth is treated with 
nitric acid a solution of bismuth trinitrate, Bi(N0 3 ) 3 , is formed, and 
the arsenic, which is almost invariably present in bismuth, is con- 
verted into arsenic acid, and combining with bismuth forms bismuth 
arsenate, BiAs0 4 . In order to rid the solution of the latter salt it is 
diluted with water to incipient turbidity and set aside for 24 or 36 
hours, when nearly all the bismuth arsenate will have been deposited, 
being less soluble than the nitrate ; by adding an excess of ammonia 
water to the clear solution all bismuth will be precipitated as bismuth- 
ous hydroxide, ammonium nitrate and arsenate remaining in solu- 
tion. After washing the precipitate until the washings are tasteless, 
it is redissolved in nitric acid, and this solution of purified bismuth 
trinitrate slowly added, with constant stirring, to a solution of 
alkali carbonate, when the following reaction occurs : 2Bi(N0 3 ) 3 + 
3Na 2 C0 3 + H 2 = (BiO) 2 C0 3 + H 2 + 6NaN0 3 -j- 2C0 2 . The 
final precipitate, consisting of basic bismuth carbonate, is thoroughly 
washed with water and dried with moderate heat. 

The exact composition of bismuth subcarbonate depends upon the 
degree of dilution of the sodium carbonate solution and the tempera- 
ture at which the bismuth nitrate is added and the final precipitate 
dried. The Pharmacopoeia demands that bismuth subcarbonate, upon 
being heated to redness, shall leave a yellow residue of bismuth oxide, 
Bi 2 O s , weighing from 87 to 91 percent, of the original weight of the 
sample used ; a salt of the above composition will yield 88.27 per 
cent, of oxide, and probably represents the average commercial salt 
of good quality. In England the salt is known as bismuth carbonate, 
the British Pharmacopoeia directing the use of ammonium carbonate 
in place of sodium carbonate, and assigning the formula 2Bi 2 O 2 0O 3 + 
H 2 to the finished product. 

Bismuth Subnitrate. A part of the process of manufacture of 
this salt has already been detailed in the preceding article. When a 
solution of purified bismuth trinitrate is poured into water, precipi- 
tation of a basic salt at once takes place, the nitric acid liberated, 
however, retaining some of the normal nitrate in solution. As in 



THE COMPOUNDS OF BISMUTH. 531 

the case of the subcarbonate, the composition of the precipitate will 
vary with the volume and temperature of the water used, and also 
the temperature at which the salt is dried. If precipitated with cold 
water, bismuth subnitrate is supposed to have the composition 
BiO(N0 3 ) -f H 2 ; but if washed with water for some time, a more 
basic salt results, probably of the composition JBiO(N0 3 ) -f H 2 + 
Bi(OH) 3 . 

The Pharmacopoeia requires that official bismuth subnitrate shall 
yield, when heated to redness, from 79 to 82 per cent, of its weight 
of bismuth oxide ; such a salt is represented by the formula of the 
more basic salt given above, yielding the maximum amount of 
oxide. 

Although a basic salt, bismuth subuitrate, mixed with water, shows 
an acid reaction, and should not be dispensed in mixtures containing 
alkali carbonates or bicarbonates as decomposition (often with ex- 
plosive violence) will result (see also page 298). 

In continental Europe the salt is frequently prescribed under the 
name magisterium bismuthi. 

Among the non-official compounds of bismuth the following are 
of interest : * 

Bismuth Oxide. Bi 2 O s . This compound may be conveniently 
prepared by boiliug bismuth subnitrate with solution of potassa or 
soda, washiug the resulting precipitate well with water, and finally 
drying it on a boiliug water-bath. It is officially recognized in the 
British Pharmacopoeia. Bismuth oxide is of yellowish-white color, 
and is used in the preparation of bismuth oleate. 



Bismuth Salicylate. Bi(C 7 H 5 3 ) 3 + Bi 2 3 . This salt, which, 
as shown by the formula, is a basic compound, is best prepared by 
digesting freshly precipitated bismuth hydroxide with salicylic acid 
at ordinary room temperature for 48 hours, then washing with small 
quantities of cold water until all free acid has been removed, and finally 
drying in a dark place at a low temperature. It occurs as a cream- 
colored odorless, tasteless, amorphous powder, which must be pro- 
tected from light. 

Bismuth Subgallate. This compound, which is also known as 
Dermatol, is prepared by dissolving crystallized normal bismuth 
nitrate in glacial acetic acid, diluting the solution with water, and 
adding, with constant stirring, a warm solution of gallic acid. The 
resulting precipitate is washed with water until free from nitric acid, 
and dried at 100° C. (212° F.). It is an impalpable saffron-yellow, 
odorless powder, permanent in the air, and insoluble in all ordinary 
solvents. 



532 PHARMACEUTICAL CHEMISTRY. 

Bismuth Subiodide. BiOI. This salt is obtained either by 
boiling an aqueous suspension of bismuth subnitrate with potassium 
iodide or by heating, but not boiling, a solution of normal bismuth 
nitrate with potassium iodide. In either case the bright-red or brown- 
ish-red precipitate is well washed with water, and dried at the tem- 
perature of boiling water. 



CHAPTEE LI 



THE COMPOUNDS OF COPPER, LEAD, ZINC, GOLD, AND SILVER. 



While copper and gold each furnish but one compound recognized 
in the Pharmacopoeia, the official salts of lead, silver, and zinc are 
more numerous and of greater importance, as may be seen by the 



following list : 



Official English Name. 
Copper Sulphate, 

Lead Acetate, 

Lead Carbonate, 

Lead Iodide, 

Lead Nitrate, 

Lead Oxide, 

Lead Plaster, 

Cerate of Lead Subacetate, 

Solution of Lead Subacetate, 

Ointment of Lead Carbonate, 

Ointment of Lead Iodide, 

Zinc Acetate, 

Zinc Bromide, 

Precipitated Zinc Carbonate, 

Zinc Chloride, 

Zinc Iodide, 

Zinc Oleate, 

Zinc Oxide, 

Zinc Phosphide, 

Zinc Sulphate, 

Zinc Valerianate, 

Solution of Zinc Chloride, 

Ointment of Zinc Oxide, 

Gold and Sodium Chloride, 

Silver Cyanide, 
Silver Iodide, 
Silver Nitrate, 
Diluted Silver Nitrate, 
Moulded Silver Nitrate, 
Silver Oxide, 



Official Latin Name. 
Cupri Sulphas. 

Plumbi Acetas. 
Plumbi Carbonas. 
Plumbi Iodidum. 
Plumbi Nitras. 
Plumbi Oxidum. 
Emplastrum Plumbi. 
Ceratum Plumbi Subacetatis. 
Liquor Plumbi Subacetatis. 
Unguentum Plumbi Carbonatis. 
Unguentum Plumbi Iodidi. 

Zinci Acetas. 

Zinci Bromidum. 

Zinci Carbonas Prsecipitatus. 

Zinci Chloridum. 

Zinci Iodidum. 

Zinci Oleatum. 

Zinci Oxidum. 

Zinci Phosphidum. 

Zinci Sulphas. 

Zinci Valerianas. 

Liquor Zinci Chloridi. 

Unguentum Zinci Oxidi. 

Auri et Sodii Chloridum. 

Argenti Cyanidum. 
Argenti Iodidum. 
Argenti Nitras. 
Argenti Nitras Dilutus. 
Argenti Nitras Fusus. 
Argenti Oxidum. 



The Compounds of Copper. 

Copper Sulphate. CuS0 4 -|-5H 2 0. The crude salt, known in 
commerce as blue vitriol, is not suited for pharmaceutical purposes, on 
account of the impurities (iron and other metals) present ; and, as 
these cannot be removed by simple recrystallization, a better article 
may be obtained by direct solution of metallic copper in diluted sul- 



534 PHARMACEUTICAL CHEMISTRY. 

phuric acid aided by a little nitric acid, the following reaction taking 
place: Cu 3 +3H 2 S0 4 +2HNO s =3CuS0 4 +2NO+4H a O. The solu- 
tion may be concentrated and allowed to crystallize or evaporated with 
frequent stirring, so that the salt will be obtained in the form of a 
coarse granular powder, which latter is more convenient for dispens- 
ing purposes. 

The official crystallized cupric sulphate, containing 36.1 per cent, 
of water, slowly effloresces upon exposure to air ; hence it must be 
kept in tightly closed vessels. When deprived of all of its water of 
crystallization at a temperature of 200° C. (392° F.), the anhvdrous 
salt forms a valuable dehydrating agent and is used in the preserva- 
tion of absolute alcohol. 

Among the non-official compounds of copper the following may 
be mentioned as of interest to pharmacists : 

Copper Arsenite. CuHAs0 3 . This salt, which of late years 
has come somewhat into prominence, is obtained as a green pre- 
cipitate by decomposing a solution of cupric sulphate with potas- 
sium arsenite. 

Copper Acetate. Cu(C 2 H 3 2 ) 2 -j-H 2 0. Crystallized cupric 
acetate, which was recognized in the Pharmacopoeia of 1880, may be 
obtained by double decomposition of cupric sulphate and lead or 
calcium acetate ; the solution after filtration is acidulated with acetic 
acid, concentrated and allowed to crystallize. This salt must not be 
confounded with ordinary verdigris, a basic cupric acetate, which oc- 
curs in amorphous masses and has the composition, Cu 2 0(C 2 H 3 2 ) 2 . 

Copper Nitrate. Cu(N0 3 ) 2 -j-3H 2 0. A very deliquescent salt 
recognized in the British Pharmacopoeia and prepared from metallic 
copper by solution in diluted nitric acid and subsequent crystalliza- 
tion. 

Copper Alum. By this name the German Pharmacopoeia recog- 
nizes a mixture of alum, saltpetre, cupric sulphate, and camphor, 
which has also received the official Latin title, cuprum aluminatum. 
It is prepared by fusing together 16 parts each of potassium alum, 
cupric sulphate, and potassium nitrate, and adding to the fused mix- 
ture, after removal from the fire, 1 part each of powdered camphor 
and powdered potassium alum ; after thorough incorporation of the 
powders the mass is poured out on a slab to solidify. This mixture 
is sometimes prescribed by physicians as lapis divinus. 

The Compounds of Lead. 

Lead Acetate. Pb(C 2 H 3 2 ) 2 +3H 2 0. This salt may be ob- 
tained by dissolving lead oxide in diluted acetic acid, or by exposing 



THE COMPOUNDS OF LEAD. 535 

lead in the form of sheets to the combined action of air aud vinegar. 
The resulting solutions are filtered, concentrated, and crystallized ; 
in order to secure perfect crystallization a little acetic acid is added 
to the liquid. Purified lead acetate for dispensing purposes is pre- 
pared in granular form by dissolving the large crystals in water, 
filtering and evaporating the solution with frequent stirring, so that 
small crystals may be produced. 

Commercially, lead acetate is better known as sugar of lead, on 
account of its peculiar sweet taste. When exposed to the air it 
effloresces and slowly absorbs carbon dioxide ; it must therefore be 
preserved in well- closed bottles or cans. 

Lead Carbonate. 2PbC0 3 +Pb(OH) 2 or Pb 3 0(C0 3 ) 2 . As 
shown by the chemical formula, the official lead carbonate is not a 
normal carbonate, but a mixture of the same with lead hydroxide. 
It is obtained in various ways, known respectively as Dutch, Ger- 
man, French, and English methods, all of which have in view the 
preliminary preparation of basic lead acetate, which is then converted 
into basic carbonate by means of carbon dioxide. 

Commercial lead carbonate, better known as white lead, occurs of 
variable composition, the proportion of lead hydroxide being much 
greater in some samples than in others. The Pharmacopoeia demands 
the absence of more than 1 per cent, of insoluble foreign matter, 
such as sand and lead, barium and calcium sulphate ; the yield of 
85 per cent, of oxide upon strong ignition corresponds to a compound 
of the above composition. 

Lead carbonate is the most poisonous of all lead compounds ; 
hence, care must be observed in its application to excoriated surfaces. 
It is recognized in the German Pharmacopoeia as Cerussa. 

Lead Iodide. Pbl 2 . This salt is prepared by double decompo- 
sition between cold solutions of lead nitrate and potassium iodide ; 
the precipitate is well washed with water and dried at a gentle heat. 
Lead acetate may be used in place of the nitrate, but entails a loss 
of the product, since lead iodide is appreciably soluble in potassium 
acetate solution. 

Lead iodide may be adulterated with lead chromate, which re- 
sembles it in appearance ; such an admixture can be detected by 
treatment with a hot solution of ammonium chloride, in which lead 
iodide is soluble, while lead chromate remains unaffected. 

Lead Nitrate. Pb(N0 3 ) 2 . While metallic lead is soluble in 
diluted nitric acid, lead oxide or carbonate is preferred for the manu- 
facture of this salt, as solution can be effected more readily ; the 
solution of lead nitrate thus obtained is concentrated and crystallized. 
Lead nitrate is insoluble in alcohol, and in this respect differs 
from lead acetate, which is soluble in five times its weight of that 
liquid. 



536 PHARMACEUTICAL CHEMISTRY. 

Lead Oxide. PbO. Of the different oxides of lead occurring 
on the market, only that more particularly known as litharge is of- 
ficially recognized. It is obtained by heating lead in contact with 
air, to a temperature of about 400° or 450° C. (752° or 842° F.), 
and also as a by-product in the treatment of silver ores by the pro- 
cess known as cupellation. 

When lead oxide is exposed to the air it slowly absorbs moisture 
and carbon dioxide, a basic lead carbonate being formed, hence it 
should be kept in well-closed vessels ; the Pharmacopoeia limits the 
increase in weight due to such absorption to 2 per cent. The color 
of commercial litharge is not uniform, which is due to the manner 
of cooling the molten mass ; if allowed to cool slowly, a reddish- 
yellow product is obtained, while if cooled rapidly, a yellowish-red 
color results. 

Solution of Lead Subacetate. An aqueous liquid containing 
in solution about 25 per cent, of basic lead acetate of the approxi- 
mate composition, Pb 2 0(C 2 H 3 O 2 ) 2 . The official directions for pre- 
paring this well-known solution are to boil for half an hour a mix- 
ture of 17 parts of lead acetate, 10 parts of lead oxide, and 80 
parts of distilled water, supplying from time to time the water lost 
by evaporation, and finally adding to the cooled liquid enough boiled 
distilled water to bring the total weight up to 100 parts, after which 
the mixture is filtered. 

The lead acetate should be dissolved in water first and the lead 
oxide then added in the form of a finely sifted powder ; both com- 
pounds must be free from carbonate. Distilled water, preferably 
that which has been boiled, so as to avoid the presence of carbon 
dioxide, as well as sulphates and chlorides, should always be used 
in the preparation of this solution. The process of boiling the mix- 
ture is directed mainly for the purpose of economizing time, as the 
same changes will take place even at ordinary temperatures, several 
days, however, being required, together with frequent agitation of 
the vessel. 

Several basic lead acetates are known, the composition of which 
depends upon the proportions in which the lead acetate and oxide 
are employed ; thus the United States and British Pharmacopoeias, 
using the acetate and oxide in the proportion of their molecular 
weights, obtain in solution the basic compound indicated by the for- 
mula, Pb 2 0(C 2 H 3 2 ) 9 , according to the equation, (Pb(C 2 H 3 2 ) 2 +3H 2 0) 
+ PbO=Pb 2 0(C 2 H 3 2 ) 2 +3H 2 0, while the German and French Phar- 
macopoeias, directing the use of three parts of lead acetate to one of 
lead oxide, cause the production of a less basic compound, as shown 
by the equation, 2(Pb(C 2 H,0 2 ) 2 +3H.,O)+PbO=Pb 3 O(C 2 H 3 O 2 ),+ 
6H 2 0. 

In the preparation of this solution other basic lead acetates, such 
as Pb 3 2 (C 2 H 3 2 ) 2 , are also formed in small quantities in addition 
to those already mentioned, and an insoluble white residue is always 



THE COMPOUNDS OF ZIXC. 537 

left, consisting of a very basic compound, probably having the com- 
position, Pb 6 O 5 (C 2 H 3 2 ) 2 . 

Solution of lead subacetate, commercially known as Goulard's 
Extract, is very sensitive to carbon dioxide, the least exposure to air 
causing a film of basic lead carbouate to form ; hence it must be 
preserved in tightly stoppered bottles, and should always be filtered 
in a closely covered funnel. It is incompatible with solution of 
acacia, differing in this respect from the normal acetate. 

The valuation of solution of lead subacetate is made by precipita- 
tion with normal sulphuric acid, lead sulphate being formed, accord- 
ing to the equation, Pb 2 0(C 2 H s 2 ) 2 +2H 2 S0 1 =2PbS0 4 +2HC 2 H s 2 
-|-H 2 0, which also shows that each Cc. ^H 2 S0 4 corresponds to 
0.13662 Gm. of basic lead acetate of the approximate composition 
indicated by the Pharmacopoeia. For 13.67 Gm. of the solution 
about 25 Cc. of normal acid will be required, as 25 per cent, of 
13.67 is 3.4175, and 3.4175.-^-0.13662=25.01. Methyl-orange has 
been selected as an indicator, since it can be used in the presence of 
free acetic acid (being unsuited for organic acids), which is not the 
case with litmus and some other color indicators ; it causes a crimson 
color with sulphuric acid, and thus indicates the end reaction very 
sharply against the white background formed by the suspended lead 
sulphate. 

The Pharmacopoeia also recognizes a dilute solution of lead sub- 
acetate, made by mixing 3 volumes of the above solution with 97 
volumes of distilled water. This preparation is popularly known as 
lead-water. 

The Compounds of Zinc. 

Zinc Acetate. Zn(C 2 H 3 2 ) 2 -}-2H 2 0. This salt may be pre- 
pared by solution of either zinc oxide or carbonate in hot, moder- 
ately diluted acetic acid. After filtration the solution is allowed to 
cool, when a large portion of the newly formed salt separates. A 
further yield of crystals may be obtained by concentration of the 
mother-liquor. It is better to crystallize the salt from a slightly acid 
solution, so as to avoid the formation of basic zinc acetate. 

Zinc acetate upon exposure to air slowly effloresces and loses acetic 
acid, a basic salt being formed at the same time ; hence it should be 
preserved in well-stoppered bottles. 

Zinc Bromide. ZnBr 2 . The most convenient method for pre- 
paring this salt is digestion of pure granulated zinc with a solution 
of hydrobromic acid as long as reaction continues, then filtering and 
evaporating the solution to dryness. Zinc bromide may, however, 
also be obtained by mutual decomposition between zinc sulphate and 
potassium bromide or by the direct action of bromine on metallic 
zinc in the presence of water. 

Zinc bromide is a very deliquescent salt, and must therefore be 
kept in bottles closed with glass stoppers coated with paraffin. The 



538 PHARMACEUTICAL CHEMISTRY. 

Pharmacopoeia requires absolute purity for this salt, allowing merely 
traces of moisture, which is determined by titration with decinormal 
silver nitrate solution. Since each molecule of dry zinc bromide re- 
quires two molecules of silver nitrate for complete precipitation, 0.3 
Gm. will require 0.45289 Gm. of the silver salt ; this quantity is 
represented by 26.71 Cc. of j-q AgN0 3 solution. 

Precipitated Zinc Carbonate. This compound is obtained 
by mutual decomposition between zinc sulphate and sodium carbon- 
ate. On mixing cold solutions of these two salts, normal zinc car- 
bonate is precipitated in a gelatinous form, but rapidly undergoes 
decomposition, carbon dioxide being liberated, whereby a portion of 
the precipitate is again dissolved. If, however, the solution of zinc 
sulphate be added slowly and with constant stirring, to a boiling 
solution of sodium carbonate, carbon dioxide is rapidly expelled and a 
basic zinc carbonate precipitated, thus, 5(ZnS0 4 -+- 7H 2 0) -f- 5(Na 2 C0 3 
+ 10H 2 O) = (2ZnC0 3 + 3Zn(OH) 2 ) + 5Na 2 S0 4 -f 3C0 2 + 82H 2 ; 
the mixture is boiled for a short time, after which the precipitate is 
washed with water until all sodium sulphate is removed and then 
dried at a gentle heat. Potassium carbonate is not so well adapted 
as the sodium salt for the process, as the resulting potassium sul- 
phate is less readily washed out, and ammonium carbouate is unsuit- 
able, since it does not completely precipitate the zinc. 

The composition of commercial zinc carbonate will naturally vary 
with the particular process employed in its manufacture and the rela- 
tive proportions of the two salts used. The British Pharmacopoeia 
assigns the formula, ZnC0 3 + 3Zn(OH) 2 +H 2 0, to the official article, 
thereby indicating a more basic compound than the one above men- 
tioned. 

Impure native zinc carbonate, contaminated with iron, is known 
in commerce as calamine, and was at one time used in pharmacy for 
the preparation of Turner's Cerate. 

Zinc Chloride. ZnCl 2 . This salt may be obtained by evap- 
orating the official solution of zinc chloride to dryness, with constant 
stirring, adding toward the close of the operation a little hydro- 
chloric acid to avoid, as far as possible, the formation of oxychloride. 
Owing to the very hygroscopic character of the salt, it must be trans- 
ferred while still warm to perfectly dry bottles, which should be 
closed with paraffined glass stoppers. 

The entire absence of basic salt in zinc chloride is scarcely possible, 
and the Pharmacopoeia prescribes the limit by directing that 1 drop 
of hydrochloric acid shall clear up the opacity caused in 5 Cc. of a 
5 per cent, aqueous solution of the salt by the addition of an equal 
volume of alcohol. If flocculi are observed in a solution of zinc 
chloride, they are evidence of the presence of oxychloride, and should 
be removed by the cautious addition of dilute hydrochloric acid. 
As zinc chloride acts destructively upon vegetable fibre, strong 



THE COMPOUNDS OF ZINC. 539 

solutions of it should always be filtered through asbestos or glass 
wool. 

The Pharmacopoeia demands that the official salt shall contain 
99.84 per cent, of pure ZnCl.,; each Cc. of y^-AgN0 3 solution cor- 
responds to 0.006792 Gm. ZnCl 2 , hence 0.3 Gm. of the salt will re- 
quire 44.1 Cc. for complete precipitatiou, as 99.84 per cent, of 0.3 
is 0.29952 and 44.1 X 0.006792=0.29952. 

Zinc Iodide. Znl 2 . This salt can be prepared by direct union 
of iodine and zinc in the presence of water, when zinc iodide will 
be formed with liberation of hydrogen. The solution thus obtained 
is evaporated, with constant stirring, to dryness, the resulting salt 
resembling zinc bromide in appearance. Upon exposure to air zinc 
iodide is gradually oxidized, iodine being liberated and the salt be- 
coming colored, hence it must be kept in small, tightly stoppered 
vials; like the bromide it is also very deliquescent. 

Zinc iodide should contain not less than 98.62 per cent, of pure 
Znl 2 , which is ascertained by titration with decinormal silver nitrate 
solution ; each Cc. of the latter corresponds to 0.015908 Gm. Znl 2 , 
0.5 Gm. of the official salt will require, therefore, not less than 31 
Cc, for 98.62 per cent, of 0.5 is 0.4931, and 0.4931 -f-0.015908= 
31. If 31.4 Cc. y^-AgNOg solution be required for complete pre- 
cipitation of 0.5 Gm. of zinc chloride, the salt is absolutely pure 
and dry, but if more be necessary, zinc bromide or chloride is present. 

Zinc Oxide. ZnO. For pharmaceutical purposes zinc oxide is 
usually obtained by heating precipitated zinc carbonate in a crucible 
until all carbon dioxide and water have been expelled, the process 
being identical with that for the production of magnesia ; thus, 
2ZnC0 3 -f-3Zn(OH) 2 =5ZnO+2C0 2 -f 3H 2 0. A red heat is not 
necessary, decomposition already taking place at a temperature of 250° 
or 280° C. (482° or 536° F.). The lower the temperature employed 
for expelling the carbon dioxide the whiter will be the oxide obtained, 
a full, red heat always causing a decided yellow tint. 

Zinc oxide is occasionally designated asflores zinci (flowers of zinc), 
nihil album (white nothing), or lana philosophica (philosopher's wool), 
and an impure gray variety was formerly used under the name tutia 
or tutty. 

Zinc Phosphide. Zn 3 P 2 . Phosphorus and zinc may be made to 
unite by carefully adding small pieces of the former to fused zinc 
contained in a crucible, but it is difficult to obtain a product of 
uniform composition. A more desirable method for preparing the 
compound is that of Proust, whereby a mixture of hydrogen phos- 
phide and nitrogen is passed into a porcelain tube containing metallic 
zinc heated to redness, the metal combining with the phosphorus, 
while the nitrogen and liberated hydrogen escape together. 

Zinc phosphide must be preserved in tightly stoppered vials, as, 



540 PHARMACEUTICAL CHEMISTRY. 

upon exposure to air, it slowly emits phosphorous vapor, indicating 
decomposition and oxidation. 

Zinc Sulphate. ZnS0 4 +7H 2 0. This salt is manufactured on 
a large scale by digesting metallic zinc with diluted sulphuric acid, 
when zinc sulphate is formed and hydrogen eliminated. As iron is 
generally present in zinc, this also is dissolved and is removed by first 
converting it into a ferric salt (by passing chlorine into the solution) 
and afterward adding zinc carbonate, whereby all iron is precipitated 
as ferric hydroxide. The solution of zinc sulphate is separated by 
filtration, concentrated, and allowed to crystallize. 

Commercial zinc sulphate frequently contains free acid, and is 
usually contaminated with iron and other metals ; for pharmaceutical 
purposes only the purified salt in small crystalline granules should 
be used. On account of the acid reaction of an aqueous solution of 
zinc sulphate with litmus paper, free acid to be detected must be ex- 
tracted with alcohol, which has no effect on the salt, as directed in 
the Pharmacopoeia. 

Zinc Valerianate. Zn(C 5 H 9 2 ) 2 +2H 2 0. When hot solu- 
tions of sodium valerianate and zinc sulphate are mixed double de- 
composition takes place, sodium sulphate and zinc valerianate being 
produced, the former of which remains in solution, while a portion 
of the zinc salt separates in the form of scaly crystals and rises to 
the surface ; a further yield of crystals may be obtained upon con- 
centration of the mother-liquor. The crystals are afterward drained, 
washed with small quantities of cold water, and dried at ordinary 
temperature. 

Solution of Zinc Chloride. An aqueous solution of zinc 
chloride, ZuCl 2 , containing about 50 per cent, of the anhydrous salt. 
The official directions for preparing this solution are to digest metal- 
lic zinc with moderately diluted hydrochloric acid until the acid is 
saturated ; the solution is decanted, and after the addition of a small 
quantity of nitric acid evaporated to dryness ; the dry mass is next 
heated to fusion at a temperature not exceeding 115° C. (230° F.), 
allowed to cool and dissolved in sufficient water to bring the weight 
of the solution up to 1000 Gm. for every 840 Gm. of hydrochloric 
acid and 240 Gm. of zinc employed. Finally some zinc, carbonate 
is added, the mixture agitated occasionally during 24 hours, allowed 
to settle, and the clear liquid decanted. 

The object of adding nitric acid to the solution is to convert any 
iron present (derived from the zinc) into ferric chloride. To remove 
any nitrogen compounds or nitrate formed, the liquid is further evap- 
orated to dryness and fused below 115° C. (230°. F.), so as to avoid 
volatilization of any zinc chloride. The final addition of zinc car- 
bonate precipitates all iron as ferric hydroxide, and thus a solution 
of zinc chloride only is obtained. 



THE COMPOUNDS OF GOLD. 541 

Solution of zinc chloride has a specific gravity of about 1.535 at 
15° C. (59° F.), and is chiefly used for disinfecting purposes. It is 
practically identical with Burnett's disinfecting fluid. 

Besides the foregoing compounds of zinc the following are of in- 
terest : 

Zinc Hypophosphite. Zn(H 2 P0 2 ) 2 -j-H 2 0. This salt may be 
conveniently prepared by dissolving zinc oxide or carbonate in hypo- 
phosphorous acid and allowing the solution to crystallize. 

Zinc Lactate. Zn(C 3 H 5 2 ) 2 -|-3H 2 0. If moderately dilute 
lactic acid be neutralized with zinc carbonate, heating the mixture if 
necessary, and the resulting solution concentrated and set aside to 
cool, crystals of the above composition will be obtained. 

Zinc Phosphate. Zn 3 (P0 4 ) 2 -j-4H 2 0. When a hot solution of 
zinc sulphate is added to a hot solution of official sodium phosphate, 
a white crystalline precipitate of zinc phosphate results, which is 
subsequently washed with water to remove all sodium salt and then 
dried at ordinary temperature. 

Zinc Salicylate. Zn(C 7 H 5 3 ) 2 +3H 2 0. This salt may be 
conveniently obtained by gradually adding to a hot mixture of 
the salicylic acid and water an aqueous suspension of zinc oxide as 
long as solution is effected, which is then filtered and allowed to 
crystallize. 

Zinc Sulphocarbolate. Zn(S0 3 C 6 H 4 OH) 2 +8H 2 0. This salt 
may be prepared by mutual decomposition between solutions of barium 
or lead sulphocarbolate (see sodium sulphocarbolate) and zinc sul- 
phate, filtering the mixture and evaporating the clear liquid to crys- 
tallization. The British Pharmacopoeia recommends simple satura- 
tion of sulphocarbolic acid with zinc oxide. Crystals of zinc sul- 
phocarbolate are of a reddish color unless the solution has been 
acidulated with sulphuric acid. 



The Compounds of Gold. 

Gold and Sodium Chloride. The official preparation is not 
the true double salt of the same name, but a mixture of gold chloride 
and sodium chloride. The double chloride of gold and sodium, 
known also as sodium chloroaurate, contains about 76 per cent, of 
pure auric chloride, whereas, the official compound contains but 50 
per cent. The exact composition of commercial gold and sodium 
chloride depends upon the mode of preparation ; a simple mechani- 
cal mixture made by triturating sodium and gold chlorides together 



542 PHARMACEUTICAL CHEMISTRY. 

in equal proportions would be in conformity with the official defini- 
tion, but if the preparation is made after the method directed in the 
German Pharmacopoeia, a mixture of the true double salt and sodium 
chloride is sure to result ; by adding a solution of sodium chloride 
to one of an equal weight of auric chloride and evaporating the mix- 
ture to dryness, a similar preparation is possibly obtained. 

Anhydrous auric chloride, AuCl 3 , may be prepared by dissolving 
gold in nitromuriatic acid, evaporating the solution to dryness, dis- 
solving the residue in water, and carefully evaporating the liquid to 
dryness at a temperature not exceediug 150° C. (302° F.); this oper- 
ation is necessary to free the salt from acid, but a higher temperature 
must be avoided, lest decomposition of the auric chloride into aurous 
chloride and chlorine occur. 

A solution of metallic gold in a mixture of nitric and hydro- 
chloric acids contains chloroauric acid, according to the equation, 
Au 2 +2HN0 3 +8HCl=2HAuCl 4 or2(AuCl 3 +HCl)+2NO+3H 2 0, 
and by adding to such a solution sodium chloride, the double salt, 
sodium chloroaurate, is obtained upon evaporation, thus : HAuCl 4 
-fNaCl=NaAuCl 4 or (AuCl 3 +NaCl)H-HCl. For the formation 
of this compound 5.187 parts of auric chloride require 1 part of 
sodium chloride ; hence, if equal parts of the two salts are used a 
large excess of the sodium chloride will be present. 

The amount of gold present in any sample of the commercial 
double chloride can be ascertained by treatment with an excess of 
some reducing agent, whereby metallic gold is precipitated. Either 
ferrous sulphate or oxalic acid may be employed, the reaction occur- 
ring being illustrated by the following equations : 2AuCl 3 -f 6(FeS0 4 
+ 7H 2 0)=Au 2 +2(Fe 2 (S0 4 ) 3 ) + Fe 9 Cl 6 -f 42H 2 or 2AuCl 3 -f-3(H 2 C 2 
4 +2H 2 0)=Au 2 +6C0 2 +6HCl + 6H 2 0. From the second equa- 
tion it is seen that 377.1 parts of crystallized oxalic acid can precip- 
itate 393.4 parts of metallic gold; hence, in the official test, 0.15 
Gm. of the metal will require 0.143 Gm. of the acid, thus insuring 
the necessary excess of the latter. 

Gold chloride being readily reduced by contact with organic mat- 
ter, all such mixtures should be avoided, and as the official prepara- 
tion is chiefly used in pill-form, non-oxidizable excipients only should 
be employed (see also page 313). 



The Compounds of Silver. 

Silver Cyanide. AgCN". This salt may be prepared either 
by passing freshly distilled hydrocyanic acid into a solution of silver 
nitrate or by adding a solution of the latter salt to a solution of pure 
potassium cyanide as long as a precipitate continues to be formed. In 
either case the precipitate must be well washed with water and dried 
in a dark place. 

Silver cyanide becomes discolored upon exposure to light, and must 



THE COMPOUNDS OF SILVER. 543 

therefore be kept in dark bottles. It is used in pharmacy solely for 
the extemporaneous preparation of diluted hydrocyanic acid. 

Silver Iodide. Agl. When a solution of silver nitrate is 
added slowly and with constant stirring to a solution of potassium 
iodide, a light-yellowish precipitate of silver iodide is formed by 
mutual decomposition, which, after being well washed with water, 
may be dried upon paper. Owing to the very slight solubility of 
silver iodide in ammonia water, contamination with silver chloride 
or bromide can be readily detected by the pharmacopceial tests. If 
absolutely pure the salt remains unaltered by exposure to light, but 
the commercial article usually assumes a greenish tint. 

The salt is scarcely ever used in medicine now, and its recognition 
in the Pharmacopoeia appears quite superfluous. - 

Silver Nitrate. AgN0 3 . This salt is preferably made from 
pure silver, and in order to obtain a product free from acid the 
metal is dissolved in nitric acid, the solution evaporated to dryness, 
the residue fused and redissolved in water, the solution filtered and 
allowed to crystallize. The evaporation to dryness and fusion of 
the residue are for the purpose of expelling any uncombined acid 
present, which, if the first solution were allowed to crystallize, 
would, to some extent, be mechanically retained within the crystals ; 
a temperature exceeding 200° C. (392° F.) must, however, be 
avoided, lest some of the silver nitrate be reduced to nitrite. 

Silver nitrate is easily decomposed by contact with organic matter, 
and when exposed to light gradually assumes a gray color ; hence 
proper precautions must be observed in keeping and dispensing it. 

The Pharmacopoeia requires absolute purity for crystallized silver 
nitrate, which is determined by titration with decinormal sodium 
chloride solution. The equation, AgN0 3 -f-NaCl=AgCl + NaN0 3 , 
shows that 169.55 parts of the silver salt require 58.37 parts of 
sodium chloride for complete precipitation; hence each Cc. -^-Nad 
solution corresponds to 0.016955 Gm. AgN0 3 , and 0.34 Gm. of 
crystallized silver nitrate requires 20 Cc. of the decinormal solution, 
for 0.016955X20=0.35910. 

Diluted Silver Nitrate. This preparation differs from the 
preceding in containing only 33 1-3 per cent, of pure silver nitrate, 
and being much milder in its action, is also known as mitigated 
caustic. It is made by fusing together 30 parts of silver nitrate and 
60 parts of potassium nitrate, and, when a smooth, uniform mixture 
results, pouring the molten mass into suitable moulds, usually of a 
narrow cone shape. 

The amount of pure silver nitrate present in any sample may be 
ascertained by means of decinormal sodium chloride solution, an 
excess of which is added and determined subsequently by retitration 
with decinormal silver nitrate solution, using potassium chromate as 



544 PHARMACEUTICAL CHEMISTRY. 

an indicator. The two solutions being of equal value volumetrically, 
the number of Cc.-^ AgN0 3 solution required, after addition of 20 Cc. 
Y^NaCl solution in the official test, to cause a permanent red precip- 
itate of silver chromate, subtracted from 20 gives the exact number 
of Cc. ^NaCl solution necessary to precipitate all the silver from 1 
Gm. of diluted silver nitrate ; this number multiplied by 0.016955 
and then by 100 gives the percentage of silver nitrate present in the 
sample. 

Moulded Silver Nitrate. Under this name the Pharmaco- 
poeia recognizes a mixture of silver nitrate and chloride, containing 
5 per cent, of the latter salt, and prepared by adding 1 part of hydro- 
chloric acid to 25 parts of pure silver nitrate, melting the mixture 
at as low a temperature as possible and casting the mass in moulds. 
The object of converting a part of the silver nitrate into chloride is 
to render the resulting mass less brittle. 

The synonym, lunar caustic, given to this preparation in the Phar- 
macopoeia does not correspond with the same term commercially, 
which is usually applied to pure silver nitrate moulded into sticks, 
as also indicated in the British Pharmacopoeia. The latter authority 
applies the name toughened caustic to a mixture of 95 parts of silver 
nitrate and 5 parts of potassium nitrate. 

The valuation of fused silver nitrate is made exactly as in the case 
of diluted silver nitrate. Like all silver salts, this one must also be 
protected from light to prevent discoloration. 

Silver Oxide. Ag 2 0. This compound may be obtained by 
adding a solution of pure silver nitrate to a solution of potassa, soda, 
or lime, washing the resulting precipitate well with water and finally 
drying the same on a water-bath. Ammonia water is not suitable 
for the process, since it forms a soluble compound with the oxide, 
having the composition Ag^O-J-JSTHg. 

When ignited in a porcelain crucible, silver oxide should yield 
93.1 per cent, of its weight of metallic silver. Like silver iodide, 
the oxide is very rarely employed in medicine at the present time. It 
is quickly decomposed by oxidizing agents, and must never be trit- 
urated with organic substances. 



ORGANIC SUBSTANCES. 



Under this head are classified those many compounds of carbon, 
hydrogen, and oxygen, frequently associated with nitrogen, sulphur, 
phosphorus, and other elements, which are chiefly derived from the 
vegetable kingdom ; a few are also obtained from the animal king- 
dom, and some are produced synthetically. 

Prior to 1828, when Woehler announced to the scientific world 
the successful synthetic production of urea, an excretory product of 
the animal economy, solely from inorganic material, thereby estab- 
lishing the intimate relationship between organic and inorganic mat- 
ter, the agency of a peculiar vitalizing force was considered essential 
for the formation of all so-called organic bodies. No elements un- 
known to the mineral kingdom have ever been found in organic bodies, 
and the one feature which serves to distinguish this very large class 
of chemical compounds from those commonly designated as inor- 
ganic substances, is the invariable presence of carbon ; the term 
carbon compounds is therefore most appropriately applied to them. 

The simplest form of carbon compounds are the hydrocarbons, 
composed exclusively of carbon and hydrogen ; of these, two, meth- 
ane, CH 4 , and benzene, C 6 H 6 , may be said to be the source of all 
organic compounds, the constitution of which has thus far been 
studied and explained. The derivatives of these two hydrocarbons 
differ so widely in their properties that they have been conveniently 
grouped into two main classes, designated as fatty and aromatic com- 
pounds respectively. 

It is not within the scope of this book to enter into a detailed 
study of the so-called organic substances, and attention will be given 
Only to those of pharmaceutical interest. 



36 



CHAPTEE LII. 

CELLULOSE AND ITS DEEIVATIVES. 

All plants are made up of certain proximate principles, to which 
they owe their growth and value as nourishing or medicinal agents. 
The most widely diffused substance in the vegetable kingdom is cel- 
lulose or cell membrane, which goes to make up the body of all 
plants. During the growth and development of plants, some of the 
cell membraue undergoes a change, becoming gradually hard and 
woody ; to this modified form of cellulose the name liguin has been 
given, and the woody fibre of plants is assumed to be a combination of 
cellulose and lignin, called lignose. Cellulose and lignin being insol- 
uble in all ordinary solvents, the chief object in pharmaceutical pro- 
cesses is to extract from them, by appropriate treatment, the many 
valuable principles they often enclose and upon which the medicinal 
value of vegetable drugs depends. 

Lignin has not yet been obtained in a pure state, but pure cellu- 
lose has been isolated as a colorless, odorless, and tasteless gelatinous 
mass, which, upon drying, forms a horny substance, or may be ob- 
tained as a w T hite powder. It is soluble in a solutiou of cupric hy- 
droxide in ammonia water, known as Schweitzer's reagent, forming 
a mucilaginous fluid which, after dilution, admits of filtration, and, 
upon addition of an acid, is again precipitated. The elementary 
composition of pure cellulose corresponds to the formula, C 6 H 10 O 5 , 
or multiples thereof, as C ]2 H 20 O 10 or C 18 H 30 O 15 . 

Cellulose is officially recognized in the form of gossypium, or cot- 
ton, and patent lint and paper are further examples of it. When 
heated with potassium or sodium hydroxide it is gradually converted 
into oxalic acid, alkali oxalates being formed, and, if boiled with 
diluted sulphuric acid, dextrin is produced, which is finally changed 
into dextrose, from which alcohol can be obtained by fermentation. 
Immersed in strong sulphuric acid, cellulose undergoes conversion 
into a substance called amyloid, upon which the preparation of 
parchment paper depends, the pores of the paper becoming filled 
with this modified cellulose, and thus made tough and impervious to 
water. Prolonged contact of the paper with strong sulphuric acid, 
however, is hurtful, the resulting product becoming friable ; hence 
the best results are obtained if the paper be simply drawn through a 
mixture of two parts of concentrated sulphuric acid and one part of 
water, and then immediately well washed in water. 

Official purified cotton, commercially better known as absorbent 



CELLULOSE AND ITS DERIVATIVES. 547 

cotton, is prepared by first boiling carefully carded cotton in a weak 
alkaline solution, for the purpose of removing fatty matter, after 
which it is rinsed in water and immersed in a weak solution of 
chlorinated lime. It is subsequently washed in water slightly acidu- 
lated with hydrochloric acid and again well rinsed in water. If the cot- 
ton still retains fat, the treatment with alkali is repeated until the final 
product is found completely absorbent. For the more thorough re- 
moval of water after washing the cotton, recourse is had to centri- 
fugal machines by means of which the material is rapidly dried. 

Medicated cotton is usually prepared by impregnating absorbent 
cotton w T ith a solution of the medicinal agent in alcohol and glycerin 
and subsequently drying; the glycerin not being volatilized serves 
as an adhesive agent for retaining the active ingredient on the fibre 
of the cotton. The solution is used of a definite strength and in 
such quantity that the whole of it will be absorbed by and saturate 
the material. Benzoated, borated, carbolated, iodized, salicylated, 
and other medicated cotton is prepared in this or a similar manner. 
The percentage of medicinal agent present must be calculated on the 
basis of finished product, irrespective of any adhesive agent that may 
have been employed, and which naturally forms a part of the finished 
product ; thus, 25 Gm. of 10 per cent, borated cotton should contain 
2.5 Gm. of boric acid or 10 Gm. of 5 per cent, carbolated cotton 
should contain 0.5 Gm. of pure carbolic acid, etc. It has been 
suggested that impregnation of cotton with a 5 or 10 per cent, 
solution of any medicinal agent would coustitute such cotton a 5 or 
10 per cent, medication ; but such an assumptiou is erroneous, since 
the absolute quantity of medicinal agent retained by the cotton must 
always be uncertain and variable in its relation to the weight of the 
finished product. 

Cellulose and lignose both furnish most valuable pharmaceutical 
derivative products, the former by appropriate treatment with nitric- 
acid and the latter by dry distillation. 

Pyroxylin. Under this name the United States and British 
Pharmacopoeias recognize a compound soluble in a mixture of alco- 
hol and ether, and better known as collodion cotton, since it is used 
extensively in the preparation of collodion ; the name colloxylin is 
also used as a synonym in this country. In Continental Europe the two 
terms are not considered synonymous, the name pyroxylin being applied 
to insoluble gun-cotton, and colloxylin to the soluble collodion cotton. 
Pyroxylin is officially prepared by macerating purified cotton in a 
cooled mixture of 14 volumes of nitric acid and 22 volumes of sul- 
phuric acid until the cotton has become soluble in a mixture of 1 
volume of alcohol and 3 volumes of ether, then removing all adher- 
ing acid by washing first with cold and then with boiling water and 
finally drying the product in small portions at a moderate heat (60° 
C. (140° F.) ). 

When cotton is thoroughly imbued with strong nitric acid, cellu- 



548 PHARMACEUTICAL CHEMISTRY. 

lose nitrates and water are formed ; thus, C 6 H 10 O 5 -f 2HN0 3 = 
C 6 H 8 (N0 3 ) 2 3 +2H 2 0. The exact character of the reaction depends 
upon the strength of the acid used, the temperature at which the 
cotton is immersed, and the length of time maceration is continued ; 
thus, di-, tri-, tetra-, penta-, and hexanitrate may be produced. The 
last two compounds are insoluble in alcohol and ether, and hence 
unfit for the purposes of official pyroxylin, which latter probably 
consists of a mixture of cellulose di- and trinitrate. It is important 
that the acids used be of official strength, and that the acid mixture, 
which becomes heated, be allowed to cool down to 32° C. (90° F.) 
before the cotton is added, otherwise, in the latter case, the higher 
nitrates are formed and the staple of the cotton is destroyed ; if weak 
acids be employed, prolonged maceration becomes necessary and im- 
perfect nitration may result ; in either case the product is insoluble. 

In order that the cotton may be completely saturated with the 
acid mixture, it should be introduced in small portions, by the aid of 
a glass rod. The sulphuric acid used takes no part in the reaction, 
but facilitates the same by removing the water which is eliminated. 

Pyroxylin was at one time looked upon as a nitro substitution com- 
pound, and called nitrocellulose, the group N0 2 having been sup- 
posed to replace hydrogen in cellulose. Further studies of cellulose 
and the behavior of pyroxylin toward reagents have shown the latter 
compound to be a nitric acid ester or compound ether, formed by the 
displacement of hydrogen in the hydroxyl groups by the nitric acid 
radical, as shown by the formulas, C 6 H 8 (ON0 2 ) 2 3 or C 6 H 7 (ON0 2 ) 3 2 . 
The correctness of this view is shown by the fact that nitric acid can 
be abstracted from cellulose nitrates by treatment with alkalies, and 
can also be completely displaced by concentrated sulphuric acid, even 
in the cold. All cellulose nitrates can be converted back into cellu- 
lose by reducing agents, and the degree of nitration can be definitely 
determined by treatment with ferrous sulphate and hydrochloric 
acid, the nitric oxide liberated being collected in a graduated tube, 
and from this the amount of nitric acid present can be calculated ; 
the following equation explains the reaction : 2C 6 H 7 (ON~0 2 ) 3 2 -f- 
18HC1 + 18FeS0 4 = 2C 6 H 10 O 5 + 6NO + 6Fe 2 (S0 4 ) 3 + 3Fe 2 Cl 6 + 
6H 2 0. 

Pyroxylin is used in pharmacy exclusively in the preparation of 
plain and medicated collodion (see page 284), but has met with more 
extensive application in the arts in the manufacture of celluloid, a 
mixture of pyroxylin and camphor. 

The Pboducts of Distillation. When wood is subjected to 
heat in air-tight cylinders or retorts a number of new substances are 
obtained, as a result of destructive distillation, the character of which 
depends largely upon the degree of heat employed and the care with 
which the process has been conducted. Both liquid and gaseous 
products are formed and distil over, while the solid residue is either 
charcoal or the original wood employed, but slightly altered in 



CELLULOSE AND LTS DERIVATIVES. 549 

appearance. The liquid distillates include au acid fluid aud tar ; 
the former is known as pyroligneous acid or wood vinegar, which 
contains, besides acetic acid, acetone, C 3 H 6 0, methyl or wood alco- 
hol, CH3OH, furfurol, C 5 H 4 2 , catechol or pyrocatechin, C 6 H 4 (OH) 2 , 
and other substances. 

Acetic Acid. Although this acid can be produced by the oxida- 
tion of weak alcoholic liquids, it is obtained for the trade by distilla- 
tion of wood. In order to avoid, as far as possible, contamination 
with empyreumatic products, the distillation is carried on at a tem- 
perature below that at which the formation of charcoal occurs, or 
below 220° C. (428° F.). At the extensive acetic acid works of E. R. 
Squibb & Sons, in Brooklyn, N. Y., oak wood cut into small pieces, 
about four inches in length, is fed into large rectangular iron retorts, 
which are then heated in appropriate furnaces and kept at a temperature 
of 205° C. (401° F.) for a period of seven days, during which time 
a slightly colored liquid, dilute crude acetic acid, distils over, the 
wood losing about one-half in weight and assuming a dark walnut 
color and slight empyreumatic odor, but retaining its original struc- 
ture and elementary composition. The acid liquid is neutralized 
with soda ash or sodium carbonate, and the resulting sodium acetate, 
having been obtained dry by evaporation, is roasted on top of the 
furnaces heating the retorts, whereby empyreumatic products are 
destroyed and water and other volatile matter driven off. Upon 
treating the sodium acetate with sulphuric acid, in suitable stills, 
purified acetic acid is recovered. 

If wood is distilled at temperatures above 230° C. (446° F.), the 
resulting wood vinegar is more or less highly colored and possesses a 
strong empyreumatic odor. It requires a more tedious process of 
purification by means of milk of lime, whereby soluble calcium 
acetate is formed and many impurities are precipitated as insoluble 
calcium compounds; the calcium' acetate can be converted into 
sodium acetate by treatment with sodium sulphate, which is then 
further purified by solution, recrystallization, roasting, etc., and is 
finally decomposed by distillation with sulphuric acid. 

Chemically, acetic acid may be looked upon as methane or marsh- 
gas (CH 4 ), in which an atom of hydrogen has been replaced by the 
carboxyl group, C0 2 H, forming a monobasic acid, thus : CH 3 C0 2 H= 
HC 2 H 3 2 . It is a remarkably stable acid, aud, although rich in 
oxygen, is not decomposed at moderately high temperatures, nor is it 
readily affected by oxidizing or reducing agents. 

The Pharmacopoeia recognizes three grades of acetic acid, which 
are officially designated as glacial acetic acid, acetic acid, and diluted 
acetic acid, and contain, respectively, 99, 36, and 6 per cent, of ab- 
solute HC 2 H 3 2 . The three acids, recognized by the same names 
in the British Pharmacopoeia, correspond very closely in strength 
to the above, containing 99, 33, and 4.27 per cent, of absolute 
acetic acid respectively ; but in the German Pharmacopoeia the term 



550 PHARMACEUTICAL CHEMISTRY. 

acetic acid is used to designate a solution containing 96 per cent, 
of absolute acid, while the German diluted acetic acid contains 30 
per cent. 

Specific gravity is of no value in the examination of acetic acid, 
since the maximum density is reached in an 80 per cent, solution ; 
beyond this point the specific gravity again decreases until absolute 
acetic acid is reached, having a density of 1.053. Official glacial 
acetic acid and an acid of 46 per cent, have the same specific gravity, 
1.058, at 15° C. (59° F.), and, if diluted with water, the density of 
the weaker acid only will fall, that of the stronger acid increasing ; 
between 73 and 84 per cent, acetic acid the specific gravity is almost 
stationary, the rise between these two points amounting to not more 
than 8 ten thousandths. Titration with normal alkali solution, as 
directed in the Pharmacopoeia, is the only correct means of ascertain- 
ing the strength of acetic acid solutions, each Cc. of |KOH solution 
corresponding to 0.05986 Gm. of absolute HC 2 H 3 2 , as shown by 
the equation, KOH+HC 2 H 3 2 =KC 2 H 3 2 -hH 2 0. 

Glacial acetic acid is obtained by distilling anhydrous sodium 
acetate with highly concentrated sulphuric acid and exposing the re- 
sulting liquid to a temperature below 10° C. (50° F.); after crystal- 
lization has taken place, the remaining liquid may be drained off and 
again exposed to cold to secure a further yield of crystals. Glacial 
acetic acid of official strength should retain its crystalline form at 
least until a temperature of 15° C. (59° F.) is reached, when it slowly 
begins to liquefy ; much of the so-called glacial acetic acid of com- 
merce is simply a strong solution, containing from 75 to 85 per cent, 
of absolute acid and does not solidify at a temperature of 5° C. (41° 
F.) or even lower. 

The Pharmacopoeia directs the use of glacial acetic acid in the 
preparation of solution of ferric acetate, and it is also employed as an 
excellent solvent for certain essential oils, resins, and fatty bodies. 
The acid absorbs moisture from the air, and must therefore be pre- 
served in tightly-stoppered bottles. 

Official acetic acid is obtained, like the glacial acid, by distilling 
sodium acetate with sulphuric acid and finally adjusting the strength 
to the requirements of the Pharmacopoeia. It should contain 36 per 
cent, of absolute acetic acid, and is used in pharmacy chiefly for the 
preparation of the official diluted acid, and also as an addition to the 
menstruum employed for tincture of sanguinaria and several fluid and 
solid extracts. 

Acetic acid for pharmaceutical purposes should be free from ernpy- 
reuma, which may be detected by means of potassium permanganate, 
the color of which is readily discharged by empyreumatic substances. 
Upon neutralizing the acid with alkali and warming no foreign odor 
should be perceptible. 

Pharmacists will find it to their interest to purchase strong acetic 
acid and dilute this to suit their requirements, according to the rule 
given on page 65. Acetic acid of 60 and 80 per cent, strength can 



CELLULOSE AXD LTS DERIVATIVES. 



551 



Fig. 



be purchased from reliable manufacturers at relatively lower prices 
than the official acid. 

During the past few years many experiments have been made with 
the view of utilizing a strong (60 per cent.) acetic acid in place of 
alcohol for the extraction of aromatic, alkaloidal, and resinous princi- 
ples from vegetable drugs. The results thus far obtained have been 
very encouraging, and manufacturers have already successfully ap- 
plied this new menstruum in the preparation of certain aromatic solu- 
tions. 

As the Pharmacopoeia requires the official acetic acid to contain 36 
per cent, of absolute HC 2 H 3 2 , each gramme of the acid will neu- 
tralize exactly 6 Cc. of normal potassium hydroxide solu- 
tion. The commercial variety of acetic acid known as u No. 
8" should never be used in place of the official acid, as it is 
weaker, containing only 30 per cent, of absolute acid. 

Diluted acetic acid, recommended in the Pharmacopoeia 
in place of commercial vinegar as a menstruum for several 
official preparations, is made by mixing 100 Gm. of the 
36 per cent, acid with 500 Gm. of water, and contains, 
therefore, 6 per cent, of absolute HC 2 H 3 2 . Its advan- 
tages over ordinary vinegar are purity and uniformity of 
strength, besides which the entire absence of color enables 
it to be used for colorless solutions, such as spirit of Min- 
dererus and the like. 

While titration with normal alkali solution is always to 
be preferred as a means of ascertaining the strength of 
dilute solutions of acetic acid, other methods are also em- 
ployed, such as neutralization with sodium or potassium 
bicarbonate, or with a standard ammonia solution, in an 
instrument known as Otto's acetometer, see Fig. 280. The 
latter method is largely used in vinegar establishments and 
gives results accurate to within one-fifth of one per cent. 
The acetometer consists of a graduated glass cylinder with 
rounded bottom, 36 centimeters (14.4 inches) in length and 
3 centimeters (0.8 inch) internal diameter. The lower two 
graduations, marked a and b, indicate a volume of 1 and 
10 Cc. respectively, while the upper part, from b to 12, 
is divided into 48 spaces each equivalent to 0.52 Cc, hence 
the large space between any two figures represents 2.08 Cc. 
The solution of ammonia used for the test contains 1.4 
per cent, of absolute NH 3 , and is prepared by mixing 14 Gm. of 
official 10 per cent, ammonia water with 86 Gm. of distilled water ; 
every 2.07 Gm. of the solution measure 2. OS Cc. and correspond to 
0.1 Gm. of absolute HC 2 H 3 2 . When vinegar is to be tested, 1 Cc. 
of litmus test-solution is first poured into the tube, 10 Cc. of vinegar 
are then added, whereby the color of the litmus solution is changed 
to red, and finally sufficient of the above mentioned ammonia solu- 
tion until, with gentle agitation, the blue color of the liquid is 



552 PHARMACEUTICAL CHEMISTRY. 

restored. From the volume of ammonia solution used, as shown 
by the graduated cylinder, the amount of absolute acetic acid present 
can be readily calculated. 

When chlorine is allowed to act on acetic acid in the sunlight, 
chloracetic acid is formed, three varieties of which are known, the 
most important being trichloracetic acid, HC 2 C1 3 2 . This latter com- 
pound occurs in deliquescent crystals, and is obtained by treating 
chloral hydrate with fuming nitric acid, exposing the mixture to 
sunlight for several days until red fumes are no longer evolved and 
then distilling. 

Among the substances associated with acetic acid in crude wood 
vinegar are two of greater interest to pharmacists than the rest — ace- 
tone and methyl alcohol. Acetone, C 3 H 6 or CH 3 COCH 3 , also 
known as pyroacetic spirit, was heretofore obtained on a commercial 
scale solely by the destructive distillation of acetates (chiefly calcium 
acetate), but recently (1895) a process has been devised by Dr. E. R. 
Squibb for decomposing acetic acid vapor at a high temperature, be- 
tween 500° and 600° C. (932° and 1112° F.), in a specially con- 
structed iron rotary apparatus, whereby a large yield of fairly pure 
acetone may be secured. The crude acetone thus obtained is after- 
ward purified by dehydration with caustic lime and redistillation. 
The decomposition of acetic acid vapor results in the formation of ace- 
tone and carbon dioxide with the liberation of water, thus : 2HC 2 H 3 2 
=C 3 H 6 0-|-C0 2 -f H 2 The process and apparatus are fully de- 
scribed in Ephemeris, vol. iv., No. 3. 

Chemically, acetone, belongs to the class of compounds known as 
ketones, which consist of two alcohol radicals united by means of the 
bivalent group CO, called carbonyl ; hence acetone is also called 
dimethyl ketone, and may be looked upou as acetic aldehyde, 
CH 3 COH, in which the hydrogen atom is replaced by the methyl 
group. 

Acetone is now extensively employed for the manufacture of chlo- 
roform, and has been found a valuable solvent for oleoresins, collo- 
dion cotton, etc. When pure it is a colorless, mobile, inflammable 
liquid of 0.7966 specific gravity at 15° C. (59° F.), and boiling at 
56.3° C. (133.34° F.). It is miscible in all proportions with water 
and alcohol, hence the commercial article is usually contaminated 
with these substances. 

Methyl alcohol, or wood alcohol, CH 3 OH, also known as pyrox- 
ylic spirit, or wood naphtha, boiling at a comparatively low temper- 
ature — 66° C. (150.8° F.) — may be obtained in a crude state by 
distilling wood vinegar after neutralizing with sodium carbonate or 
lime, and collecting the first portions coming over ; wood vinegar 
usually contains about 10 per cent, of wood alcohol. It is purified 
by heating in a water-bath, with an excess of anhydrous calcium 
chloride, with which methyl alcohol forms a crystalline compound, 
CaCl 2 -f 4CH 3 OH, and, after all volatile matter has been dissipated, 
mixing the crystals with water and distilling, whereby the compound 



CELLULOSE AND ITS DERIVATIVES. 553 

is split up and dilute methyl alcohol recovered, which is subsequently 
dehydrated with lime and redistilled. Methyl alcohol has been used 
in England and Germany for the purpose of rendering ordinary or 
ethyl alcohol unfit for other than technical uses, by mixing the two 
liquids together ; in Germany a further addition of allyl alcohol and 
acetone is prescribed. Ethyl alcohol thus mixed is known in 
England as methylated spirit, and in Germany as denaturated alco- 
hol ; it is not subject to excise tax. 

Tar and its Derivatives. Like wood vinegar, tar is a com- 
plex mixture containing different resins, oils, hydrocarbons, phenols, 
etc., and yields valuable medicinal products. Official tar is derived 
from pine wood, and is recognized in the Pharmacopoeia as Pix 
Liquida, or liquid pitch ; by distillation it yields the official oil of tar 
and a hard residue known as black pitch. 

The most valuable derivative of wood tar is creosote, a mixture of 
phenol-like bodies consisting chiefly of guaiacol and creosol. Beech- 
wood tar is richer in creosote than that derived from other w r oods, 
containing usually about 5 per cent., and is therefore a more econom- 
ical source. Upon distilling the tar, a light and a heavy oily layer 
are obtained, together with an acid aqueous distillate ; the heavy oil 
is subsequently treated with a concentrated solution of sodium car- 
bonate, to remove acid constituents, and again distilled. That por- 
tion of the second distillate heavier than water, and consisting of 
impure creosote, is dissolved in a moderately strong solution of 
potassa or soda ; any oily layer separating is removed, and the 
creosote precipitated by saturating the alkaline solution with sul- 
phuric acid. The alternate treatment with alkali and acid is repeated 
until the alkaline solution is practically free from color and does not 
turn brown on heating. The precipitated creosote is finally washed 
with a weak alkaline solution and water, and distilled, that portion 
distilling between 200° and 220° C. (392°-428°^\) being collected. 

As wood vinegar also contains small proportions of creosote, the 
latter is recovered therefrom by first separating the oily constituents 
by saturating the liquid with sodium sulphate, treating these with 
sodium carbonate solution, distilling, and proceeding further as 
above. 

When first distilled, creosote is colorless, but gradually assumes a 
yellowish tint, and, as found in commerce, is rarely free from color ; 
upon exposure to air the color darkens materially. Much of the 
commercial creosote is coal-tar creosote or partially rectified carbolic 
acid, consisting largely of cresols, and is totally unfit for medicinal 
use; for dispensing purposes only the official beechwood creosote 
should be employed, which may readily be distinguished from car- 
bolic acid by its peculiar odor, its lesser solubility in water, and its 
immiscibility with a mixture of glycerin and water. 

The name creosote was given to this liquid on account of its power 
of preserving meat, and is derived from two Greek words — xo-a^ > 



554 PHARMACEUTICAL CHEMISTRY. 

flesh, and aco^ecv, to save, to preserve. Creosote was first separated 
from wood tar in 1832. 

Whenever creosote is to be dispensed in solution in plain water or 
lime water the resulting mixture should invariably be passed through 
a pledget of cotton, as small particles of insoluble matter frequently 
separate, particularly in the case of lime-water mixtures. 

Of late years creosote has been largely superseded by guaiacol, 
its chief constituent, upon which the value of creosote no doubt 
wholly depends. Guaiacol is contained in creosote to the extent of 
from 60 to 90 per cent., and is obtained from it by fractional distil- 
lation, that portion distilling between 200° and 205° C. (392° and 
401° F.) being collected as crude guaiacol ; this is treated with am- 
monia to remove acid compounds, and again distilled. The lower 
boiling fraction is collected, dissolved in ether, and treated with alco- 
holic solution of potassa, which causes the separation of potassium- 
guaiacol, C 6 H 4 KOCH 3 , the latter being insoluble in ether. After 
thorough washing with ether the compound is crystallized from 
alcohol, decomposed by means of diluted sulphuric acid, and the 
liberated guaiacol again rectified. Guaiacol is rarely found abso- 
lutely pure in commerce, but can be obtained by treating pure ben- 
zoylguaiacol with alcoholic solution of potassa, and subsequently 
washing and rectifying the product; among chemists guaiacol is also 
known as methylcatechol, being the methyl ether of catechol (pyro- 
catechin), C 6 H 4 (OH)OCH 3 . (A more complete account of the prop- 
erties and various combinations of guaiacol may be found in the 
National Dispensatory, 5th ed., p. 799.) 



CHAPTER LIII. 

THE DERIVATIVES OF COAL TAR. 

During the destructive distillation of coal, itself a modified form 
of wood, the result of slow decomposition caused by decay and fer- 
mentative action, gaseous as well as liquid products are obtained, be- 
sides a solid residue known as coke, the process being similar to that 
occurring in the distillation of wood. The gases are used extensively 
for illuminating and heating purposes, while the coal tar which con- 
tains benzene, C 6 H 6 , toluene, C 7 H 8 , aniline, C 6 H 5 NH 2 , naphtalene, 
C 10 H 8 , carbolic acid, C 6 H 5 OH, and other important substances, is 
further distilled and furnishes, besides a solid residue, known as pitch 
or asphalt, a light and a heavy oil from which the above compounds 
are extracted. 

The distillate of coal tar known as light oil consists chiefly of 
hydrocarbons of various boiling points, which can be separated from 
each other by fractional distillation. The most important of these 
is benzene, C 6 H 6 , designated by many as benzol, which furnishes a 
number of valuable derivative products ; it is obtained by collecting 
that portion of light oil distilling between 80° and 90° C. (176° and 
194° F.), purifying the same by exposing it to a low tempera- 
ture, when it crystallizes and is freed from adhering liquid impurities 
and redistilling. Benzene has a specific gravity of 0.880 at 15° C. 
(59° F.), and is soluble in four parts of alcohol ; it must not be 
confounded with benzin, a mixture of hydrocarbons obtained by dis- 
tillation from coal oil or petroleum. The latter substance is recog- 
nized in the Pharmacopoeia and is also known as petroleum ether ; 
it has a specific gravity of about 0.670 at 15° C. (59° F.), boils 
between 50° and 60° C. (122° and 140° F.), and requires not less 
than six parts of alcohol for solution. Both liquids are readily in- 
flammable and must be preserved with care ; they have been found 
valuable solvents for fats, resins, caoutchouc, volatile oils, and some 
alkaloids, and are used in plant analysis. 

Benzene is extensively employed in the manufacture of aniline, 
which in turn is used for the preparation of certain valuable phar- 
maceutical products, such as acetanilid, antipyrine, etc. When ben- 
zene is added in small portions to warm, fuming, nitric acid, a dark 
red liquid is formed, from which, upon the addition of water, an 
oily precipitate is obtained, known as nitrobenzene, C 6 H 5 X0 2 . 

By the action of nascent hydrogen, subsequent mixture with milk 
of lime and distillation, nitrobenzene is made to yield a basic fluid, 
called aniline. It has the composition' C 6 H 5 NH 2 , and is also known 



556 PHARMACEUTICAL CHEMISTRY. 

as araidobenzene or phenylamine ; when pure and recently obtained, 
it is a colorless oily liquid, but darkens upon exposure to air. 

Acetanilid. C 6 H 5 NHC 2 H 3 0. The only derivative of aniline 
recognized in the Pharmacopoeia is acetanilid, also known as phenyl- 
acetamide. The term anilid is applied to a class of compounds de- 
rived from aniline by replacement of one or both hydrogen atoms of 
the amido group, NH 2 , by alcohol or acid radicals, hence both alco- 
hol and acid anilids are known to chemists. Acetanilid is prepared 
by heating in a flask connected with a reflux condenser, a mixture 
of equal parts of aniline and glacial acetic acid, until a small portion 
of the mixture removed from the flask congeals on cooling; the mass 
is then distilled, when water and acetic acid first pass over, and after- 
ward acetanilid, which is subsequently recrystallized from boiling 
water. The reaction involved in this process consists in the forma- 
tion of aniline acetate, which, upon heating, is split up into acetanilid 
and water, as shown by the equation, C 6 H 5 NH 9 +HC 2 H 3 2 ==C 6 H 5 
NHC 2 H 3 0+H 2 0. 

The name autifebrin has also been given to acetanilid, but being a 
proprietary name has not been officially accepted as a synonym in 
most countries, although it is recognized iu the Austrian Pharmaco- 
poeia. A compound closely allied to acetanilid is commercially 
known as exalgine ; it is methylacetanilid, C 6 H 5 NCH 3 C 2 H 3 0, and 
differs from acetanilid in having both hydrogen atoms of the amido 
group replaced, oue by an alcohol radical, the other by an acid radical. 

Antipyrine is also prepared from aniline by a complicated process. 
It has not been introduced into the United States Pharmacopoeia, 
but is recognized in the German and British Pharmacopoeias, being 
designated as Phenazone by the latter authority. Antipyrine is a 
well-characterized base and forms salts with acids by direct addition. 
Its constitution is indicated by its chemical name, dimethylphenyl- 
pyrazolon, but the copyrighted name, antipyrine, is usually employed 
by physicians and in commerce ; such names as analgesine, metho- 
zine, anodynine, and parodyne have also been used as synonyms. 
Antipyrine is not used so freely now as formerly, and has been found 
to be incompatible with numerous drugs, such as sodium bicarbonate 
and salicylate in solid form, chloral hydrate, spirit of nitrous ether, 
tinctures containing tannin, etc. 

Resorcin. C 6 H 4 (OH) 2 . Another derivative of benzene used in med- 
icine is resorcin. Although first discovered by fusion of certain resins, as 
those of ammoniac, galbanum, guaiacum, asafetida, etc., with potassa, 
it is now manufactured on a large scale from benzene by first heating 
the latter with fuming sulphuric acid to 275° C. (527° F.), whereby 
benzene metadisulphonic acid, C 6 H 4 (HS0 3 ) 2 , is formed. This acid 
is neutralized with milk of lime, decomposed with sodium carbonate, 
and the solution of sodium benzene-metadisulphonate thus obtained 
evaporated to dryness ; the residue fused for several hours with sodium 



THE DERIVATIVES OF COAL TAB. 557 

hydroxide yields sodium resorcin and sodium sulphite. Boiliug an 
aqueous solution of the saline mass expels sulphurous acid and, upon 
extracting the tar-like residue with ether and distilling, impure resor- 
cin is obtained, which is purified by sublimation aud recrystallization 
from water. 

Resorcin is chemically known as metadioxybenzene, which shows 
it to be a diatomic phenol, C 6 H 4 (OH) 2 ; two isomerides are also 
known, namely, ortho-and paradioxybeuzene, designated as catechol 
or pyrocatechin and hydroquiuol or hydroquinone respectively. The 
term resorcinol is given as a synonym in the Pharmacopoeia, but this 
name has also been applied to a proprietary preparation composed of 
equal parts of resorcin and iodoform fused together, hence confusion 
is apt to arise. 

Pure resorcin occurs in colorless crystals, which readily assume a 
pink tint, and finally turn red upon exposure to air and light ; it 
must, therefore, be carefully preserved, in tightly-stoppered bottles, 
in a dark place. Solutions of resorcin also become rapidly colored, 
hence should always be dispensed in dark amber-colored vials. 

Carbolic Acid. C 6 H 5 OH. This substance is chiefly met with 
in the heavy oil distilled from coal tar, better known as dead oil. 
Crude carbolic acid, which is also recognized in the Pharmacopoeia, 
is obtained by collecting that portion of dead oil distilling between 
150° and 200° C. (302° and 392° F.) and twice redistilling the 
same between 160° and 190° C. (320° aud 374° F.). It may be 
purified by agitating with warm solution of soda, whereby crystal- 
line sodium phenol, C 6 H 5 OXa, is produced, which is freed from ac- 
companying foreign matter by heating and treating with water ; the 
aqueous solution is finally supersaturated with hydrochloric acid, 
precipitating the phenol as an oily liquid. This is repeatedly shaken 
with sodium chloride solution, dehvdrated with calcium chloride and 
distilled between 165° and 185° C. (329° and 365° F.). Upon ex- 
posing the distillate to a low temperature, it solidifies into a crystal- 
line mass. 

Some manufacturers simply separate the pure carbolic acid from 
the crude by fractional distillation, carefully collecting that portion 
passing over between 165° and 185° C. and allowing it to crystal- 
lize. 

The Pharmacopoeia requires that carbolic acid shall contain not 
less than 96 per cent, of pure phenol and have a congealing point 
not lower than 35° C. (95° F.) and a boiling point not higher than 
188° C. (370.4° F.) Absolutely pure carbolic acid melts' at about 
41° C. (105° F.) and boils at 178° C. (350.4° F.), hence the higher 
the melting point and the lower the boiling point the purer is the 
acid. 

Of late years synthetic carbolic acid has been offered for sale. 
It is remarkably free from foreign matter, aud is obtained by treat- 
ing benzene with sulphuric acid, whereby benzenesulphonic acid, 



558 PHARMACEUTICAL CHEMISTRY. 

HS0 3 C 6 H 5 , is produced, which is then converted iDto sodium or 
potassium benzenesulphonate ; this latter compound, upon being 
fused with an excess of alkali, is converted into alkali carbolate 
and sulphite, the former of which, upon addition of hydrochloric 
acid, splits up into alkali chloride and carbolic acid. Final distil- 
lation of the carbolic acid yields a pure product. 

Several varieties of carbolic acid of American, English, German, 
and Freuch manufacture occur on the market. For dispensing pur- 
poses only the crystallized acid should be used, which can be liquefied 
on a water-bath and retained in liquid form by addition of 10 per 
per cent, of distilled water. Calvert's carbolic acid No. 1, an Eng- 
lish preparation, is of very fine quality and probably more exten- 
sively used in this country than any other variety. For disinfecting 
purposes, different kinds of crude carbolic acid, varying from a very 
dark almost black, to a nearly colorless solution, are employed ; 
they consist chiefly of cresols, C 7 H 7 OH, with varying proportious of 
phenol. 

As already stated under creosote, on page 553, the purer varieties 
of crude carbolic acid are also known as coal tar creosote, and often 
sold as commercial creosote. Carbolic acid and wood tar creosote 
differ, however, so widely in their physical and chemical properties 
that they can be readily distinguished from each other by the tests 
given in the Pharmacopoeia. 

Chemically, carbolic acid belongs to the class of compounds known 
as phenols, and, being the simplest form thereof, is often designated 
merely as phenol. The name carbolic acid was given to the sub- 
stance by Runge, who first isolated it from coal tar, on account of 
its source (carbo, coal) and its acid properties. Phenols are hydroxyl 
derivatives of benzene and other hydrocarbons of the aromatic series, 
and occur as monatomic, diatomic, and triatomic compounds, con- 
taining respectively 1, 2, and 3 hydroxyl groups ; examples of each 
class occur in the Pharmacopoeia ; thus, carbolic acid, C 6 H 5 OH, 
resorcin, C 6 H 4 (OH) 2 , pyrogallol, C 6 H 5 (OH) 3 . 

The Pharmacopoeia directs that the amount of absolute phenol 
present in carbolic acid shall be determined volumetrically by pre- 
cipitation of the phenol as tribromophenol, C 6 H 2 Br 3 OH. The solu- 
tion used for this purpose is known as Koppeschaar's Solution, and 
is designated in the Pharmacopoeia as deci normal bromine solution, 
although it contains no free bromine ; it is a solution of sodium bro- 
mate and bromide in such proportions that when treated with hydro- 
chloric acid an amount of bromine is liberated corresponding to 
0.007976 Gm. for each cubic centimeter of the solution used, thus 
constituting it a decinormal bromine solution. In the official test 
an excess of this solution is added to an aqueous solution of carbolic 
acid together with some hydrochloric acid, and the excess ascertained 
by addition of potassium iodide and subsequent titration of the 
liberated iodine by means of sodium thiosulphate solution. Since 
iodine is liberated by bromine in exact molecular proportions, a cubic 



THE DERIVATIVES OF COAL TAB. 559 

centimeter of decinormal sodium thiosulphate solution corresponds 
in value to one cubic centimeter of decinormal bromine solution, and 
the number of Cc. ^ Na 2 S 2 3 solution required to decolorize the 
iodine solution subtracted from the whole number of Cc. of ^ Br. 
solution added originally, leaves the number of cubic centimeters of 
the latter solution necessary for the precipitation of all phenol present 
as tribromophenol. 

Four distinct reactions occur during the performance of this test before 
the data necessary for the calculation of the percentage of phenol present 
are obtained, namely : 1. The liberation of bromine by means of 
hydrochloric acid, thus NaBrO s + 5NaBr + 6HCl=6NaCl + Br 6 
-f- 3H 2 ; 2. The precipitation of tribromophenol, thus C 6 H 5 OH -f- 
Br 6 =C 6 H 2 Br 3 OH + 3HBr ; 3. The liberation of iodine, thus 2KI 
-j- Br 2 =2KBr + 1 2 ; 4. The decoloration of the iodine solution, 
thus 2Na 2 S 2 3 -f I 2 =2NaI + Na 2 S 4 6 . The second equation shows 
that 93.78 parts of absolute phenol require 478.56 parts of bromine 
for complete precipitation ; hence each Cc. of the bromine solution 
corresponds to 0.001563 Gm. of C 6 H 5 OH, for 478.56:93.78:: 
0.007976 : 0.001563. If 0.039 Gm. of carbolic acid be used for 
the volumetric test, 24 Cc. of decinormal bromine solution will be 
required to show 96 per cent, of absolute phenol, for 96 per cent, of 
0.039 is 0.03744 and 0.001563 X 24=0.037512. 

Among the derivatives of carbolic acid is one, which, although 
not officially recognized, is extensively employed in medicine, and 
appears in both the German and British Pharmacopoeias, namely, 
phenacetin. The process for its preparation is a complicated one, 
paranitrophenol being first obtained by acting on carbolic acid 
with diluted nitric acid ; this is converted into a sodium compound, 
then into paranitrophenetol by the action of ethyl iodide, and finally 
into paraphenetidin by means of nascent hydrogen. By boiling with 
glacial acetic acid paraphenetidin is converted into para-acetphen- 
etidin or phenacetin, C 6 H 4 0C 2 H 5 NHC 2 H 3 O. It occurs as a crystal- 
line powder or in the form of colorless scaly crystals, and is sparingly 
soluble in water. 

Naphtalene (also written Naphtalin). C 10 H 8 . This hydrocar- 
bon exists like benzene in coal tar ; it is found in the so-called heavy 
oil, and is deposited as a dark- colored crystalline substance from the 
fraction collected between 180° and 250° C. (356° and 482° F.). Crude 
naphtalene is purified by successive treatment with caustic soda and 
sulphuric acid, to remove acid and basic by-products, after which it 
is repeatedly heated with concentrated sulphuric acid, being each 
time distilled with steam, and is finally resublimed. The white naph- 
talene thus obtained still has a tendency to darken when exposed to 
air and light, to overcome which it is treated for a short time with a 
mixture of sulphuric acid and manganese dioxide at water-bath tem- 
perature ; finally, the product is washed with weak alkaline solution 
and water and again sublimed. 



560 PHARMACEUTICAL CHEMISTRY. 

For pharmaceutical purposes, naphtalene recrystallized from alco- 
hol should alone be used. 

Naphtol. C 10 H 7 OH. This compound, belonging to the class 
of phenols, bears the same relation to naphtalene as carbolic acid 
bears to benzene. Naphtalene, when heated with concentrated sul- 
phuric acid, forms naphtalene sulphonic acid, HSO 3 C 10 H 7 , of which 
two varieties occur, designated as alpha and beta naphtalenesul- 
phonic acid ; the formation of these two acids depends upon the tem- 
perature employed, the alpha acid being produced at water-bath 
temperature and even below, and changed to the beta variety as the 
temperature is raised beyond this point. Both acids, when treated 
with milk of lime, yield the respective calcium naphtalenesulpho- 
nates, from which the corresponding sodium salts are obtained by 
decomposition with sodium carbonate. The sodium salts fused with 
caustic soda yield sodium naphtol and sodium sulphite, which, by 
treatment with hydrochloric acid, are converted into sodium chloride 
and alpha- or beta-naphtol, as the case may be. The final product 
is further purified by sublimation and recrystallization from water. 

The Pharmacopoeia recognizes only betanaphtol, and, as alpha- 
naphtol is far more poisonous than the official variety, the formation 
of beta-naphtalenesulphonic acid only is sought to be insured by 
heating the mixture of naphtalene and sulphuric acid to 200° C. 
(392° F.). 

Commercial naphtol is frequently contaminated with the alpha 
variety, for the detection of which the Pharmacopoeia gives a special 
test, depending upon the production of a crimson color changing to 
blue, when a 2 per cent, aqueous solution of naphtol is mixed with 
a trace of sugar and carefully underlaid with concentrated sulphuric 
acid. 

Naphtol furnishes a number of derivative products which have 
been introduced into medicine, such as benzouaphtol or naphtol ben- 
zoate — betol or naphtol salicylate, known also as naphtalol, naphto- 
salol or salinaphtol — hydronaphtol — asaprol or calcium naphtolsul- 
phonate — alumnol or aluminum naphtolsulphonate, etc. An account 
of these products and their properties can be found in the National 
Dispensatory, 5th edition, pp. 1073, 1074. 



CHAPTER LIY. 

STARCHES, GUMS, AND SUGARS. 

Besides cellulose, certain other principles are widely diffused in 
the vegetable kingdom, which are of more or less interest to phar- 
macists, either as useful medicinal agents or because they must be 
excluded in the preparation of certain galenicals. These are known 
as amylaceous, mucilaginous, and saccharine principles, and are 
usually designated as starches, gums, and sugars. The investiga- 
tions of Fischer and others regarding the chemical character of these 
well-known plant-products have so completely changed the view- 
formerly entertained, and so enriched the knowledge regarding their 
intimate relationship, that chemists now consider starch, gum, and 
sugar, and also cellulose, as members of a group designated as sac- 
charides ; in regard to their chemical character, they are looked upon 
as aldehydes, ketones, and anhydrides of certain hexatomic alcohols. 

Starch. This substance occurs chiefly in the seeds, roots, and 
rhizomes of plants, where it appears deposited for the purpose of 
future nourishment either of the germinating embryo or during the 
next year's growth of the plant itself. When viewed with the naked 
eye, starch appears as a structureless substance in the form of a 
powder, but under the microscope it is seen to consist of round, 
ovate, lenticular, or polyhedral granules or cells, differing in size 
and shape according to the source whence the starch has been taken, 
as may be seen in Figs. 281 to 286. Starch granules appear to con- 
sist of concentric layers of varying density, arranged around a nucleus 
or hilum situated in the centre of the granule, or more generally at 
one end or near the margin. The formation of starchy matter and 
the manner of its deposit belong more properly to the study of 
physiological botany. 

While a valuable dietetic and article of food, starch possesses little 
or no medicinal virtue, and, as its presence largely interferes with 
the stability of pharmaceutical preparations, it is sought to be 
excluded by the use of appropriate menstrua. Starch is insoluble 
in cold water, strong or diluted alcohol, and ether, but when treated 
with boiling water solution takes place and a more or less gelatinous 
mucilage results upon cooling. This peculiar behavior with water 
is due to the fact that the starch granules have a very hard outer 
coating (by some authorities looked upon as a distinct membrane), 
to which the name farinose or amylin has been given ; this is rup- 
tured by the boiling water, after which the white contents of the 

36 



562 



PHARMACEUTICAL CHEMISTRY. 



granule, known as granulose or amidin, are dissolved. Prolonged 
trituration of starch with sand causes a similar rupture of the 
farinose, when a portion of the amidin will also be taken up by 
cold water. Solutions of zinc chloride, calcium chloride, and similar 




Fig. 282. 






£o 






% ° 



Rice Starch, 



Fig. 285. 





Potato Starch. 

Fig. 286. 




Maranta Starch. 



Curcuma Starch. 



salts dissolve starch in the cold. Complete solution of the granules 
does not occur even with boiling water, as the farinose remains 
undissolved, but it can be rendered soluble by the action of sulphuric 
acid. If alcohol be added to starch mucilage, a white powder, solu- 
ble in cold water, is precipitated ; this is known as soluble starch. 
In composition starch is isomeric with cellulose, but differs from it 



STARCHES, GUMS, AND SUGARS. 563 

in physical and many chemical properties. The most delicate reagent 
for starch is iodine, which strikes a characteristic bine color with cold 
solutions of starch, and, in the form of solution, is used to detect 
starch in vegetable tissues. Conversely starch mucilage is exten- 
sively employed in iodimetry as an indicator; the union between 
starch and iodine is, however, a very feeble one, and not considered 
to be of a chemical character, as it is easilv broken up bv heat. 

When heated to 190° C. (374° F.) with glycerin, starch forms a 
transparent jelly, known as plasma, which is occasionally used as a 
vehicle for ointments. 

All air-dried starch, when heated at 100° C. (212° F.) to constant 
weight, loses about 14 per cent, of water, which is gradually reab- 
sorbed by exposure to the air ; if anhydrous starch be mixed with a 
small quantity of water it absorbs the same w 7 ith evolution of heat, 
as certain inorganic salts absorb water of crystallization. When 
heated for some time to 170°-200° C. (338°-392° F.), starch is 
gradually converted into dextrin and becomes soluble in cold water, 
losing at the same time its property of being colored blue by iodine. 
The same result occurs if starch be heated with diluted nitric or sul- 
phuric acid, the change, however, taking place in less time and at a 
lower temperature ; if the action of the diluted acids be allowed to 
continue for a longer period, the dextrin is finally converted into 
dextrose (glucose). Diastase, the active ferment of malt, also effects 
the hydrolysis of starch into dextrin, and finally into a kind of 
sugar, differing, however, from dextrose, and known as maltose; 
for this reason starch paste is used in the valuation of malt extracts. 

Dextrin is extensively made for the market from potato starch, 
either by the dry-heat process above mentioned or by mixing the 
starch into a paste with water acidulated with nitric acid, pressing 
the paste into cakes, drying, powdering, and heating for one or two 
hours at 110° C. (230° F.). Dextrin occurs in two varieties, white 
and yellow, which are soluble in cold as well as hot water, forming 
a mucilaginous liquid ; it has a sweetish taste, peculiar odor, and is 
also known as British gum. Iodine colors dextrin pink or reddish, 
unless unaltered starch is present, when a purplish tint results. 

Two substances, allied to starch and isomeric with it in composi- 
tion, are met with in certain drugs ; these are lichenin and inulin, 
the former occurring in cetraria and the latter in inula, taraxacum, 
etc. Lichenin, also known as moss-starch, is soluble in boiling 
water and gelatinizes upon cooling ; iodine imparts to it a dirty-blue 
color. Inulin forms a clear solution with boiling water and does not 
gelatinize upon cooling ; continued boiling with water converts it 
into levulose or inverted sugar. It is colored yellow by iodine and 
does not occur in the form of concentric layers, nor does it contain a 
definite and constant proportion of water like starch. 

Starch is obtained for use by washing it out from the material 
containing it with water, the mixture being transferred to large 
sieves or straining-bags, which allow the starch to pass through with 



564 PHARMACEUTICAL CHEMISTRY. 

the water and retain the cellular fibre. In the case of potatoes, 
these are first grated, while wheat, corn, etc., are treated in the form 
of flour. Since cereals contain a nitrogeuized principle or ferment, 
called gluten, intimately mixed with the starch, this is removed 
either by means of incipient fermentation not affecting the starch, or 
it may be separated by kneading the flour in muslin bags while a 
stream of water continually falling on it washes out the starch, leav- 
ing the gluten behind. The different varieties of starch can be best 
distinguished from each other by their shape and size under the 
microscope, but some show also differences in their behavior with hot 
water and also hydrochloric acid. 

Official starch, recognized in the Pharmacopoeia by the general 
Latin term amylum, is corn starch, and is used in preparing the 
official glycerite of starch. Starch was known to the ancients, who 
applied the name amylum (derived from the Greek word fioloc:, a 
millstone, and the prefix d, meaning privative or without) to the sub- 
stance, because starch could be obtained without grinding between 
stones, as in the case of flour. 

Gums. These are amorphous translucent substances, in all prob- 
ability excretory products, obtained usually as exudations. They 
differ from starch in being wholly or partly soluble in cold water 
and in not being colored blue by iodine; the blue coloration pro- 
duced in tragacanth is due solely to the presence of starch. Gums 
may be divided into two classes, which differ from each other in physi- 
cal as well as chemical properties ; for convenience they are known 
as gums and mucilages, respectively. As already stated on pages 
185 and 296, gums are precipitated from their aqueous solution by 
strong alcohol and solutions of ferric chloride and sodium borate and 
silicate, the precipitate in the last three cases being of a gelatinous 
character. Diluted alcohol, containing less than 60 per cent, by 
volume of absolute alcohol, is capable of dissolving gums (the quantity 
taken up increasing with the decreasing proportion of alcohol present), 
but glycerin has no solvent effect whatever, although it mixes clear 
with aqueous solutions of gums. The most delicate reagent for true 
gum is solution of lead subacetate, which still causes slight opales- 
cence in solutions containing 1 part of acacia in 10,000 parts of water. 

True gums consist largely of arabin or arabic acid combined chiefly 
with calcium, together with potassium and magnesium. Mucilages 
consist partly of soluble and partly of insoluble principles, and in 
some cases contain also starch. Acacia and tragacanth are the official 
representatives of the two classes in the Pharmacopoeia, but the muci- 
lages are also met with in althaea, elm bark, linseed, sassafras pith, 
etc. The soluble portion of tragacanth is not precipitated by alcohol 
or solution of lead subacetate, like arabin, and the insoluble portion 
is tinged blue by iodine, as already stated above. The so-called gum 
exuding from the cherry, peach, and plum trees must also be classed 
with the mucilages. 



STARCHES, GUMS, AND SUGARS. 565 

Arabin, to which the empirical formula C 12 H 22 O n has been assigned, 
may be obtained from mucilage of acacia, after acidulation with hydro- 
chloric acid, by precipitation with alcohol as a milk-white mass, of 
acid reaction and liberating carbon dioxide from carbonates. When 
dried it absorbs water and swells, but does not dissolve until lime- 
water has been added. 

Metarabic acid or cerasin occurs in the insoluble portion of cherry 
gum, and mav be obtained from acacia bv heating the same for some 
time at 100° C. (212° F.) ; it is soluble in alkaline liquids. 

Parabin, which is isomeric with arabin, is found in agar-agar or 
Ceylon moss ; it is without acid reaction, swells up to a jelly with 
water, and is dissolved by dilute mineral acids, but precipitated by 
alkalies and alcohol. 

Bassorin is the name given to the pectin-like principle present in 
tragacanth aud allied products. It is insoluble in cold aud hot 
water, but absorbs the same, swelling to a gelatinoid mass, and is 
soluble in alkaline liquids. Besides bassorin, the mucilages also con- 
tain soluble principles, and in some cases unaltered starch ; the 
former are not identical with arabin, being without acid reaction. 

If tragacanth be moistened with a solution of pyrogallol it gradu- 
ally blackens, whereas acacia similarly treated develops a red color, 
due to the formation of pyrogalloquinone. 

Carragheen is the mucilaginous constituent of Irish moss, or 
chondrus. It is not precipitated by alcohol, and by treatment with 
diluted sulphuric acid yields galactose. 

When treated with boiling nitric acid, gums are converted into 
mucic, saccharic, and oxalic acids. By continuous boiling with 
water acidulated with sulphuric acid, some gums yield arabinose and 
others galactose, products closely allied to the sugars ; of these, 
galactose is capable of fermentation, while arabinose is uufer- 
mentable. 

The name gum is derived from the Greek word xouuc, and this 
from the Egyptian name kami, applied to acacia, which was used 
nearly 4000 years ago as an adhesive agent in painting. 

Very closely allied to the gums are the pectous substances. 
Unripe acidulous fruits and certain succulent roots contain a pecu- 
liar body called pectose, which, under the influence of a ferment 
known as pectase in connection with light and heat, and, in the case 
of fruits, of organic acids also, is changed into pectin, and finally 
into pectosic acid or vegetable jelly, to which is due the gelatin iza- 
tion of certain fruit juices as well as the infusions of gentian, taraxa- 
cum, senega, and other roots. The alkali salts of pectosic acid being 
soluble, advantage is frequently taken of this in pharmaceutical 
preparations to prevent gelatin ization ; as, for instance, the use of 
ammonia water in fluid extract of senega. 

Unripe green fruits owe their hardness to the presence of pectose, 
and become softer as the latter is gradually changed to pectin during 
the ripening process. 



566 PHARMACEUTICAL CHEMISTRY. 

The name pectin is derived from the Greek word 7ny*ro.5, meaning 
curdled. 

Sugars. Although for pharmaceutical purposes but three kinds 
of sugar are employed, chemists include under the general term of 
sugars a much larger class of compounds, belonging to the carbo- 
hydrates and characterized by a more or less sweet taste. For con- 
venience, sugars are divided into two main groups, known as glucoses 
and saccharoses. 

Glucoses are looked upon by chemists as aldehydes and ketones, 
derived from the alcohols maunitol and dulcitol, C 6 H 8 (OH) 6 ; they 
contain two atoms of hydrogen less than these compounds, and, in 
some cases at least, are convertible into hexatomic alcohols by the 
action of nascent hydrogen. They can be obtaiued by hydrolysis 
from various other carbohydrates, and with few exceptions are 
directly fermentable. As a rule, they crystallize imperfectly or 
with difficulty. The empirical formula, C 6 H 12 6 , has been assigned 
to the members of this group, which includes dextrose, levulose, 
galactose, arabinose, sorbinose, etc. 

Dextrose is the best known member of the glucose group, occur- 
ring in commerce both in the fluid and solid form ; to the former the 
term glucose is usually applied, while the solid variety is better known 
as grape-sugar. In nature dextrose is found associated with levulose 
or fruit-sugar in numerous fruits and in honey ; it also occurs in 
certain secretions of the human body as the result of a disease known 
as diabetes mellitus. Artificially, it is manufactured on a large scale 
from corn starch by treatment with diluted sulphuric acid, the pro- 
cess being conducted in both open aud closed converters, of which 
the latter require the application of a higher heat but a shorter time 
to complete the change. As already stated on page 563, the first 
action of the diluted acid is to change the starch into dextrin, which 
is finally converted into dextrose ; liquid or syrupy glucose usually 
contains both dextrin and dextrose, while in the solid grape-sugar 
the complete conversion into dextrose has been carried out. Corn 
starch is always mixed with gluten, which is removed by treatment 
with caustic soda, after which the starch is mixed with water to a 
creamy consistence and run into the diluted acid and heated by means 
of steam until all starch has been converted ; the acid is then neutral- 
ized by means of calcium carbonate and the liquid filtered, passed 
through animal charcoal, and concentrated. 

Grape-sugar separates as a granular crystalline deposit in honey, 
and can be obtained in a hydra ted form in small, wart-like crystals 
from its aqueous or hydro-alcoholic solution ; from a hot solution in 
alcohol or methylalcohol it separates in anhydrous prismatic crys- 
tals. It is soluble in very nearly its own weight of water and in 
fifty parts of alcohol at 15° C. (59° F.), the solutions possessing 
a far less sweet taste than those of ordinary sugar. At 60° C. 



STARCHES, GUMS, AND SUGARS. 567 

(140° F.) grape-sugar softens, and at S6° C. (186.8° F.) melts com- 
pletely. 

On account of its remarkable reducing properties, dextrose has 
been used with success in the preservation of certain ferrous solutions, 
notably the syrup of ferrous iodide. It readily reduces ferric and 
cupric compouuds to the ferrous and cuprous state, and the salts of 
bismuth and silver to the metallic coudition. 

Various tests can be used for the detection of dextrose, such as 
Trommer's test (cupric sulphate, solution of potassa, and heat), causing 
a deposit of brick-red cuprous oxide; Moore's test (solution of potassa 
and heat), causing a dark, almost black color; Boettgers test (bismuth 
subnitrate, solution of potassa, and heat), causing a black precipitate 
of metallic bismuth, and others. For the quantitative determination 
of dextrose, volumetric alkaline solution of cupric tartrate, known as 
Fehling's Solution, is usually employed; each cubic centimeter of this 
solution corresponds to 0.005 Gin. of anhydrous dextrose. When 
Fehling's Solution is boiled in the presence of dextrose, yellowish 
hydrated cuprous oxide is first formed, which is finally changed into 
the anhydrous brick-red variety. Since dextrin also reduces the 
cupric salt of Fehling's Solution, its absence must first be determined 
in quantitative determinations. Barfoed's Solution, consisting of 
13.3 Gm. of crystallized cupric acetate and 2 Gm. of glacial acetic 
acid in 200 Cc. of water, suffers reduction with all glucoses, but not 
with dextrin. 

The name dextrose was given to this particular sugar on account 
of its dextro-rotatory power, since it invariably deflects the ray of 
polarized light to the right when examined by means of a polariscope. 
An explanation of the uses of the polariscope can be found on pages 
512 and 513 of the Pharmacopoeia.' 

Levulose, or fructose, is of interest chiefly as a natural constituent 
of honey ; it also occurs associated with dextrose in many fruits, and 
is therefore known as fruit-sugar. The name levulose was giveu it 
because it is lsevo-rotatory — that is, causes the plane of polarized 
light to deviate to the left. When pure, it occurs as a colorless or 
faintly yellowish syrup of very sweet taste which crystallizes with 
great difficulty ; it remains in the liquid portion of honey after all 
the grape-sugar has been removed. As stated under Starch, levulose 
is also formed by prolonged boiling of inulin with diluted acids. 
The term inverted sugar is usually applied to the mixture of dextrose 
and levulose, whether obtained by inversion of cane-sugar by means 
of diluted acids and heat, or by some special ferment, such as that 
supplied by the bees in the manufacture of honey. 

Xatural honey contains from 65 to 80 per cent, of a mixture of 
dextrose and levulose, together with small portions of caue-sugar, 
besides 20 or 30 per cent, of water and about y 1 ^ per cent, of formic 
acid. During the clarification of honey the acid is generally dissi- 
pated, and possibly on this account clarified honey is more prone to 
fermentation than the crude article. Commercial honey is frequently 



568 PHARMACEUTICAL CHEMISTRY. 

adulterated with a solution of glucose and dextrin ; the latter can 
be detected by addition of an excess of official alcohol to an aqueous 
solution of honey. Any dextrin present will be precipitated in the 
form of white flocculi. 

Saccharoses appear to be the result of a union of two molecules 
of one or any two members of the group of glucoses, water being 
eliminated at the same time, hence they may be considered as anhy- 
drides; thus, 2C 6 H 12 6 ==C 12 H 22 1 ,+H 2 0. In support of this view, 
the members of this group have been found to take up water and 
split up into equal molecules of glucoses if heated with diluted acids. 
Saccharoses are darkened by strong sulphuric acid, and form color- 
less combinations with the alkalies, differing in these respects from 
the glucoses. The more important members of the group are sucrose 
or cane-sugar, lactose or milk-sugar, and maltose or malt-sugar ; 
mycose, identical with trehalose, is of some interest as occurring in 
ergot. With the exception of malt-sugar, the saccharoses can only 
be fermented after previous conversion into one of the glucoses. 

Sucrose, or cane-sugar, officially recognized as Saccharum, is ob- 
tained from sugar-cane, sorghum, and the common European sugar- 
beet. While immense quantities of sugar are prepared iu this country 
direct from the juice of the cane, considerable amounts are also im- 
ported in the form of raw or crude sugar for refining purposes. 

The juice of the sugar-cane contains about 18 per cent, of sugar 
and 81 per cent, of water, besides traces of salts, mucus, albumen, 
etc. Having been expressed, it is mixed with milk of lime and 
heated, the greenish scum rising to the surface being removed ; the 
liquid is then strained, concentrated, and stirred while crystallizing, 
so as to prevent the formation of large crystals. The crystalline 
mass is placed into perforated hogsheads to allow the mother-liquor, 
molasses, to drain off, after which it is redissolved, the solution 
decolorized by filtration through animal charcoal, concentrated by 
evaporation in vacuum-pans at about 80° C. (176° F.), and crystal- 
lized. Finally, the crystals are drained and dried by means of large 
centrifugals, wherein the adhering mother-liquor, containing also 
inverted or so-called non-crystallizable sugar, is rapidly removed. 

The sugar-beet contains about 8 or 10 per cent, of sugar, which 
is obtained by a process similar to the above, the juice being treated 
with lime, filtered through charcoal, concentrated, and crystallized. 

Sucrose is soluble in half its weight of water at 15° C. (59° F.), 
and in 175 parts of alcohol at the same temperature ; it is thus seen 
to be more soluble in water and less soluble in alcohol than glucose. 
A saturated solution of cane-sugar at 15° C. (59° F.) contains 67.72 
per cent, of sugar and has a specific gravity of 1.345 ; one liter con- 
tains 910.8 Gm. of sugar and 434.2 Gm. of water. Official syrup is, 
therefore, a little less than saturated, containing 64.54 per cent, of 
sugar. While dextrose melts at 80° C. (176° F.), dry cane-sugar 
remains unaltered at this temperature, but melts at 160° C. (310° F.), 



STARCHES, GUMS, AND SUGARS. 569 

congealing afterward to a slightly colored, glassy mass Heated to 
180° C. (356° F.), cane-sugar splits up into dextrose and a product 
isomeric with starch and dextrin, known as levulosan ; above 205° C. 
(401° F.), a dark-brown, thick liquid of complex composition and 
bitter taste results, to which the name caramel has been given. 

If cane-sugar be heated with diluted (5 per cent.) sulphuric acid 
it is changed into inverted sugar, a mixture of equal molecules of 
dextrose and levulose, and is only then capable of fermentation ; cer- 
tain ferments produce the same effect. Sucrose is always dextro- 
rotatory, but becomes less so after inversion, as the levulose then 
present exercises its laevo-rotatory effect on the plane of light. 

The purest sugar obtainable is that known as cut loaf sugar, 
which is the best kind for the preparation of syrups and similar 
solutions, but is not so convenient for use as granulated sugar ; the 
latter, however, is generally contaminated with ultramarine, the blue 
color of which is intended to overcome the natural yellowish tint of 
the sugar. 

The official test for the presence of grape-sugar in cane-sugar 
depends upon the reduction of the silver nitrate to the metallic state 
by the dextrose, as pure cane-sugar is without effect upon it. 

Cane-sugar is used as a valuable preservative for many otherwise 
unstable solutions, and its sweet taste renders it a desirable adjuvant 
in prescriptions. It is also known to increase the solubility of several 
metallic oxides and vegetable principles. 

Lactose, or sugar of milk, which is recognized in the Pharma- 
copoeia by the latter name (Latin name, saccharum lactis), is obtained 
from the milk of mammalia, where it is found to the extent of from 
3 to 6 per cent. It is said also to exist in the fruit of Achras sapota, 
a tree of the West Indies, this being the only known case of its occur- 
rence in the vegetable kingdom. Milk-sugar is obtained by crystal- 
lization from the whey or thin fluid remaining after removal of the 
casein or albuminous principle by coagulation. The crude granular 
product is purified by resolution, filtration, and recrystallization. 
Formerly the world's supply was furnished by Europe, chiefly 
Switzerland, but now considerable quantities are manufactured in 
this country. 

The crystals of sugar of milk contain 5 per cent, of water, which 
is not lost until a temperature of 130° C. (266° F.) is reached. They 
are very hard, and require about 6 or 7 parts of water for solution, 
the solution being far less dense than one of dextrose or cane-sugar 
of equal concentration, and far less sweet in taste. As found in the 
shops, sugar of milk is always in the form of powder, which feels 
gritty between the teeth. In pharmacy, it is used exclusively as a 
diluent in the preparation of triturations, powdered extracts, etc., for 
which purposes it is admirably adapted, as it is non-hygroscopic. 

Like dextrose, sugar of milk is dextro-rotatory, and also reduces 
an alkaline solution of cupric tartrate, but does not reduce Barfoed's 
Solution of cupric acetate (see page 567). Boiled with diluted acids, 



570 PHARMACEUTICAL CHEMISTRY. 

sugar of milk yields dextrose and galactose ; the latter crystallizes in 
large prisms and yields mucic acid, insoluble in cold water when 
treated with nitric acid, whereas dextrose yields saccharic acid, which 
is soluble. 

Maltose, or malt sugar, is produced by the action of diastase of 
malt on starch, either during the germination of the barley, or when 
diastase is mixed with starch and water and kept at a temperature 
of 70° C. (158° F.). It is directly fermentable, and is of consider- 
able interest in pharmacy on account of the part it plays in the fer- 
mentation of grain in the manufacture of alcohol. Maltose crystallizes 
with one molecule of water, and is readily soluble in water; although 
strongly dextro-rotatory, it can be distinguished from dextrose, like 
milk-sugar, by means of Barfoed's Solution. 



CHAPTER LT. 

ALCOHOL AND ITS DERIVATIVES. 

Although, in chemistry, the term alcohol is used to designate 
a group of compounds derived from hydrocarbons of the methane or 
fatty series, by replacement of one or more hydrogen atoms by a cor- 
responding number of hydroxyl groups, which have certain chemical 
properties in common, it is restricted in pharmacy to one substance, 
chemically known as ethyl alcohol, and recognized in the Pharma- 
copoeia also by the simple term alcohol. When other alcohols are 
used in pharmacy they are either designated by specific names, such 
as glycerin, mannitol, etc., or by adding a qualifying prefix to the 
word alcohol, as amyl alcohol, methyl or wood alcohol, etc., to dis- 
tinguish them from ordinary or ethyl alcohol. 

Alcohol is obtained in this country almost exclusively from grain, 
while in Europe potatoes are extensively employed, by a process 
known as vinous fermentation. Fermentation is a process of decom- 
position differing from putrefaction in that the resulting products are, 
as a rule, valuable, or at least useful and not accompanied by offen- 
sive gases ; fermentatiou is usually applied to the decomposition of 
substauces composed of carbon, hydrogeu, and oxygen ; while, if 
nitrogen and sulphur are also present, the term putrefaction is more 
aptly used, on account of the putrid or foul odor emitted by such 
bodies during decomposition. Certain conditions are essential to 
both processes of decomposition, namely, the presence of air, moisture, 
heat, and certain agents known as ferments. There are fermenta- 
tions of various kinds, such as saccharine, vinous, mucic, lactic, 
butyric, and acetous, depending upon the substances under manipula- 
tion, some of these being in reality oxidation processes not due to fer- 
mentative action. 

In the manufacture of alcohol, the first step necessary is the sac- 
charine fermentation, known also as the mashing process, which con- 
sists in the conversion of starch into sugar by means of diastase. 
This latter substance is produced during the germination of grain, as 
in the malting of barley. Malt is made by well moistening barley 
with water and spreading it, about two feet deep, on stone floors, in 
dark rooms ; heat is developed, and partial germination is allowed to 
go on, during which time diastase is produced, the barley assuming a 
darker color and peculiar odor, while the starch of the grain is con- 
verted into dextrin and maltose or malt sugar. Diastase is capa- 
ble of converting 2000 times its weight of starch iuto maltose. 
When isolated, it is a white, tasteless, solid, soluble in water and weak 



572 PHARMACEUTICAL CHEMISTRY. 

alcohol, but precipitated by strong alcohol, and rendered inert by the 
heat of boiling water. 

Extract of malt, which, if properly made, should represent good 
malt in the form of a concentrated infusion, owes its value as a digestive 
agent solely to the diastase present ; therefore that extract capable of 
converting the largest amount of starch into dextrose is unquestion- 
ably the best. The following method is recommended for compara- 
tive testing of malt extracts : Dissolve 5 Gm. of extract of malt in 
sufficient distilled water to yield 100 Cc. of solution ; of this, add 5 
Cc, representing 0.25 Gm. of the extract, to 250 Cc. of cold starch 
mucilage (prepared by dissolving 30 Gm. of Bermuda Arrow Root 
in 1000 Cc. of boiling distilled water) and keep the mixture at a 
temperature of 55°-60° C. (131°-140° F.) for 30 minutes; then 
stop the diastatic action, by raising the temperature to 100° C. (212° 
F.) or by addition of 2 or 3 Cc. of a 10 per cent, sodium hydroxide 
solution, and dilute the mixture to a given volume by addition of 
water. Titrate an aliquot part of the liquid with Fehling's Solution 
(alkaline cupric tartrate volumetric solution, U. S. Ph.) and ascertain 
the amount of dextrose present, from which deduct the amount found 
in a corresponding amount of the extract of malt by previous titra- 
tion with Fehling's Solution ; the difference indicates the amount of 
sugar produced by the diastase present in the extract. Each Cc. of 
Fehling's Solution corresponds to 0.005 Gm. of anhydrous dextrose, 
or 0.0045 Gm. of starch converted thereinto. 

During the mashing process large quantities of raw grain are kept 
in contact with malt aud water at a moderately elevated temperature, 
whereby the starch is gradually all converted into dextrose, appa- 
rently by the simple appropriation of water, as shown by the follow- 
ing equations : 

1. 3C 6 H 10 O 5 + H 2 = C 12 H 22 O n -f C 6 H 10 O 5 

Starch Maltose Dextrin 

2 - C 12 rT 22 O u + C 6 H 10 O 5 -j- 2H 2 = 3C 6 H 12 O g 

Maltose Dextrin Dextrose 

The saccharine solution thus obtained is known as wort, aud, 
after addition of some yeast, is allowed to undergo fermentation at a 
temperature which is maintained between 15° and 30° C. (59° and 
86° F.), whereby a weak alcoholic liquid is produced, due to the 
splitting up of dextrose into alcohol and carbon dioxide, thus : 
C 6 H 12 6 = 2C 2 H 5 OH -f 2C0 2 . Besides alcohol and carbon dioxide, 
however, some amyl alcohol and other homologous products, col- 
lectively designated as fusel oil, are also produced, and Pasteur has 
shown that small quantities of glycerin (3 per cent.) and succinic 
acid (0.6 per cent.) are invariably formed. The composition of these 
so-called low wines or weak spirits varies with the starchy material 
used in their manufacture ; thus, potato starch always yields a much 
larger proportion of amyl alcohol than grain starch, while grain 
spirit is contaminated with oenanthic and other ethers. 



ALCOHOL AND ITS DERIVATIVES. 573 

Distillation of the fermented liquid furnishes a product much 
richer in alcohol, raw whiskey, which is then further rectified by 
treatment with recently burned charcoal and subsequent redistilla- 
tion in stills provided with a series of condensers, in the first of 
which much of the water and amyl alcohol is retained, allowing a 
purer and stronger alcohol to pass on to the other condensers. For 
the further removal of water and foreign odors from alcohol, distil- 
lation over sodium manganate, anhydrous sodium acetate and freshly 
burned lime is employed. 

During the past two or three years alcohol has been successfully 
produced from cellulose by treating dried peat with very dilute 
sulphuric acid for several hours at a temperature of 120° C. (248° 
F.), whereby peat-sugar is formed, which is subsequently fermented 
with yeast and distilled, yielding as much as 62 liters of absolute 
alcohol for 1000 kilogrammes of dry peat used (about 15 gallons for 
each ton). 

The Pharmacopoeia recognizes four d liferent grades of strength of 
alcohol, designated by specific names, thus : 

Percentage of True Ethyl Alcohol. 





Percentage 


Percentage 




by weight. 


by volume. 


Alcohol .... 


about 91.0 


94.0 


Absolute alcohol 


. 99.0 


99.5 


Deodorized alcohol . 


about 92.5 


95.1 


Diluted alcohol 


about 41.0 


48.6 



Whenever alcohol and water are mixed, heat is evolved and con- 
traction of volume results, both varying with the proportions of the 
two liquids used. According to Fliickiger, the rise of temperature 
will be greatest when 30 parts by weight of absolute alcohol are 
mixed with 70 parts by weight of water, amounting to 9° C, or 
16.2° F., and the greatest contraction occurs when 58 volumes of 
absolute alcohol are mixed with 54 volumes of water, amounting to 
a loss of 4 volumes or 3.57 per cent, of the total mixture. 

The use of the alcoholometer for ascertaining the percentage 
strength of commercial alcohol has already been fully explained on 
page 57 and rules have been given on pages 93 and 94 for prepar- 
ing weaker alcohol from a stronger variety by dilution with water. 
Besides the Pharmacopoeia gives specific directions, under Diluted 
Alcohol, for preparing mixtures of definite strength. 

Commercial alcohol does not always come up to the requirements 
of the Pharmacopoeia for official alcohol, averaging, as a rule, from 
91 to 92 per cent, by volume of ethyl hydroxide ; but the variety 
sold as Cologne spirit generally contains 94.5 or 95 per cent.; the latter 
also corresponds more closely to the official deodorized alcohol in its 
freedom from foreign odor. Alcohol which has been stored for some 
time in barrels, particularly if the latter have been imperfectly 
charred on the inside, is apt to be contaminated with coloring matter 
and tannin. 



574 PHARMACEUTICAL CHEMISTRY. 

Absolute alcohol is intended to be identical with deodorized alco- 
hol as far as the absence of amyl alcohol and other impurities is con- 
cerned, but contains far less water than the latter, the Pharmacopoeia' 
not allowing more than 1 per cent, by weight. The entire absence 
of traces of moisture is practically impossible, although the amount 
is reduced to less than \ per cent, by some manufacturers. Among 
the various dehydrating agents suggested, freshly burned lime has 
been found most desirable. Deodorized alcohol is either shaken with 
the lime in coarse powder, for some time, or caused to percolate re- 
peatedly through alternate layers of fine and coarse granules of lime, 
in an apparatus so arranged as to avoid all contact with air, after 
which it is transferred, without exposure, to a column still and dis- 
tilled at a low temperature, under reduced pressure, by which means 
it is possible to carry the alcohol vapor forward through several con- 
densing chambers, in which any aqueous moisture still remaining 
will be separated and flow back into the still. Absolute alcohol is 
very hygroscopic and should be preserved in tightly stoppered 
bottles containing either some anydrous cupric sulphate or pieces of 
freshly burned lime. In pharmacy its use is confined to that of a 
solvent for phosphorus and similar substances, but in the manufact- 
ure of certain chemicals it is more extensively employed. 

Official diluted alcohol, a most valuable solvent for many vegeta- 
ble principles, is made by mixing equal volumes of official alcohol 
and water. Since the mixture suffers nearly 3 per cent, loss by con- 
traction, the finished, cooled product contains about 48.4 per cent, 
by volume of absolute ethyl alcohol. It should not be used until 
the temperature of the mixed liquids has again fallen to that of the 
room. 

Proof spirit, as recognized by the U. S. government, contains 50 
per cent, by volume of absolute alcohol, and is reckoned by gaugers 
as equivalent to 100 degrees; hence the terms 25 or 40 above or be- 
low proof do not refer to alcoholic liquids containing 25 or 40 per 
cent, of alcohol more or less than the 50 per cent, proof spirit, but 
only one-half as much, namely, 12.5 or 20 per cent, each proof de- 
gree, representing \ per cent, of absolute ethyl alcohol. Official 94 
per cent, alcohol is thus said to stand at 188 degrees, or 88 degrees 
above proof. 

Amyl Alcohol, although not recognized in the Pharmacopoeia, 
is of interest as the source of amyl nitrite and valerianic acid and as 
a valuable solvent used in chemical research. As already stated on 
page 572, amyl alcohol and other homologous products are formed 
during the fermentation of grain or potato starch ; larger quantities 
may be obtained by continuing the distillation after ethyl alcohol 
ceases to come over. Amyl alcohol is purified by fractional distillation 
and repeated washing with a concentrated solution of table salt. It 
is a colorless, thin, oily liquid of about the same specific gravity as 
alcohol, but boiling, when pure, at 132° C. (269.6 F.). Chemically 



ALCOHOL AND ITS DERIVATIVES. 575 

it is amyl hydroxide, C 5 H n OH, and yields compounds homologous 
with those of ethyl alcohol — namely, amyl ether, (C 5 H u ) 2 0, arnyl 
aldehyde, C 5 H 10 O, and valerianic acid, C 5 H l0 O 2 . 

Derivatives of Alcohol. The following preparations made 
from ethyl alcohol are officially recognized in the Pharmacopoeia, 
and therefore of special interest to pharmacists : Ether, acetic ether, 
ethereal oil, spirit of nitrons ether, paraldehyde, chloroform, chloral 
hydrate, and iodoform. In addition, a few allied and some unofficial 
preparations will also be considered. 

Ether. The general term ether is used by chemists to designate 
anhydrides of alcohols, or oxides of hydro-carbon radicals ; both 
simple and mixed ethers are known, as the oxygen may be united to 
two groups of the same or mixed radicals; thus, (C 2 H 5 ) 2 0, ethyl ether, 
and (CH 3 ) 2 0, methyl ether, are simple ethers, while (CH 3 C 2 H 5 )0, 
methyl ethyl ether, is a mixed ether. 

The Pharmacopoeia recognizes but one compound by the name 
ether (Latin name, cether), namely ethyl ether or ethyl oxide (C 2 H 5 ) 2 0, 
and in all official formulas and physicians' prescriptions this sub- 
stance is to be understood as intended. Ethyl ether is sometimes 
called sulphuric ether, and several commercial varieties, known as 
concentrated and washed ether, are found on the market ; but, as 
their strength and purity are not stated on the label, they should not 
be used in place of the official ether. The process of ether manu- 
facture consists in heating a mixture of alcohol and sulphuric acid 
in a suitable still, by means of steam coils, to 130° C. (266° F.) and, 
when the distillation of ether begins, allowing a continuous supply of 
alcohol to flow into the still from a feed-back so regulated that the 
mixture shall be kept at a constant quantity and temperature. The 
vapors are passed through two purifiers, the first one of cast iron 
containing a solution of potassa, in which water and other impurities 
are washed out ; the second one of block tin is provided with a bed 
of pebblestones, where alcoholic and other vapors having a higher 
boiling point than ether are recondensed and carried to the feed-back 
near the still. In order that no ether may be lost, both purifiers are 
kept heated, the purified ether vapor being finally condensed in a 
large worm surrounded by running water. 

Etherification may be thus explained : when alcohol and sulphuric 
acid are mixed together, one molecule of each combines to form 
ethylsulphuric acid and water, C 2 H 5 OH -f H 2 SO,= C 2 H 5 HSO^ 
H 2 0. In the presence of heat and an excess of alcohol a further 
reaction ensues, ether bein^ produced and sulphuric acid regenerated, 
thus, C 2 H 5 HSO 4 -fC 2 H 5 OH=(0 2 H 5 ) 2 O+H 2 SO 4 . 

The theoretical yield of ether amounts to nearly five pounds for 
each gallon of alcohol used, but in practice rarely more than four 
pounds are recovered. It is important that the temperature be kept 
between 130° and 138° C. (266° and 280.4° F.), so as to avoid the 



576 PHARMACEUTICAL CHEMISTRY, 

distillation of much alcohol vapor and the formation of other com- 
pounds. Since sulphuric acid is continually regenerated its power 
of etherifyiDg alcohol is theoretically without limit, but in practice 
it is found that water aud other impurities in the alcohol gradually 
interfere, the acid being diluted and becoming black while the mix- 
ture in the still begins to froth. According to Dr. Squibb, a charge 
of 360 pounds of concentrated sulphuric acid is sufficient for the 
etherificatiou of 120 barrels of good, clean alcohol. 

Official ether has a specific gravity of 0.725 to 0.728 at 15° C. 
(59° F.) and contains 96 per cent, of absolute ethyl oxide; the re- 
maining 4 per cent, consist of alcohol and traces of water which it 
is impracticable to remove. It is best preserved in tin containers hold- 
ing from 100 Gm. upward, as they are less liable to breakage than 
glass. Ether is very inflammable, and its vapor, which is about two 
and a half times as heavy as air, when mixed with the latter explodes 
in contact with flame, hence care is necessary in handling and dis- 
pensing ether, especially at night. 

Besides being used in various official manufacturing processes, ether 
also enters into the composition of two alcoholic solutions, designated 
in the Pharmacopoeia as spirit of ether and compound spirit of ether 
(see page 238), which should be prepared by the pharmacist himself, 
on account of the variable quality of the commercial articles. 

Acetic Ether. This compound is not an ether in a chemical 
sense, but an ester, or ethereal salt, the basylous hydrogen in acetic 
acid having been replaced by the ethyl group. Much of the acetic 
ether found on the market is of inferior quality, and, as its manufac- 
ture presents no difficulties, the following process of Hager is recom- 
mended, the author having repeatedly used it with much satisfaction : 
126 Gm. of official alcohol are mixed with 218 Gm. of 94 per cent, 
or 222 Gm. of official (92.5 per cent.) sulphuric acid, and the mix- 
ture allowed to stand for two or three days in a well-closed flask, so 
that ethylsulphuric acid may form. Having rendered a quantity of 
sodium acetate anhydrous, by heating at 130° C. (266° F.) to con- 
stant weight, 164 Gm. of this acetate, in powder, are placed in a 
retort and the acid-alcohol mixture carefully added. The retort is 
heated in a water-bath and the vapors condensed in a well cooled 
receiver as long as a brisk reaction continues ; the final distillate is 
collected separately, as it is likely to be more largely contaminated 
with acetic acid. The reactions occurring in the foregoing process 
may be illustrated by the equations, C 2 H 5 OH + H 2 S0 4 =C 2 H 5 HS0 4 
+ H 2 and C 2 H 5 HSO 4 +NaC 2 H 3 2 =C 2 H 5 C 2 H 3 O 27 l-NaHS0 4 . 

Crude acetic ether is always more or less contaminated with alco- 
hol and acetic acid, which are removed by repeatedly agitating the 
ether with one-third of its volume of a 20 per cent, sodium chloride 
solution containing also 2 per cent, of sodium carbonate and carefully 
decanting the ethereal layer. Milk of lime and caustic alkalies 
cannot be used, since the acetic ether would thereby be decomposed 



ALCOHOL AND ITS DERIVATIVES. 577 

and converted into alcohol and the respective acetate. For the re- 
moval of water, the purified ether is well shaken for some time with 
freshly ignited potassium carbonate and redistilled iu a water-bath ; 
dehydrated acetic ether is far more stable than that containing water. 
Official acetic ether should be neutral to litmus paper, contain not 
less than 98.5 per cent, of ethyl acetate and be soluble in not less 
than eight parts of water at 15° C. (59° F.) ; absolute ethyl acetate 
requires about 16.5 parts of water for solution. 

Ethereal Oil. This name is applied in the Pharmacopoeia to a 
volatile liquid composed of equal volumes of so-called heavy oil of wiue 
aud ether. Heavy oil of wiue is a complex mixture of ethyl sulphate, 
(C 2 H 5 ) 2 S0 4 , and varying proportions of certain polymeric hydro- 
carbons, etherin and etherol; by some, ethyl sulphite, (C 2 H 5 ) 2 S0 3 , is 
also supposed to be present. The official directions for preparing 
heavy oil of wine are to distil a mixture of equal volumes of alcohol 
and sulphuric acid (previously allowed to stand for twenty-four 
hours, partly to separate lead sulphate), on a sand-bath, at a temper- 
ature between 150° and 160° C. (302° and 320° P.), as long as oily 
drops pass over. The ethereal liquid is separated from the distillate 
and exposed to the air to free it from ether, after which, it is drained 
on a well-wetted filter and washed with cold water. Pure heavy oil 
of wine is a yellowish, somewhat thick, oily liquid of a peculiar 
aromatic odor and having a specific gravity of 1 .13 at 15° C. (59° F.). 
Diluted with an equal volume of ether, it constitutes official ethereal 
oil, a pale yellowish liquid, of 0.910 spec. grav. at 15° C. (59° F.). 

Ethereal oil is used solely in the preparation of the official com- 
pound spirit of ether, in which it is present to the extent of 2.5 per 
cent, by volume (see page 238). 

Much confusion exists regarding the so-called ethereal oil and 
heavy oil of wine of different manufactures, and some care is neces- 
sary in the purchase of the commercial article. As the yield of 
heavy oil of wine does not average over two per cent, of the weight 
of alcohol used, it stands to reason that careful producers cannot 
furnish true ethereal oil at low figures. 

Spirit of Nitrous Ether. The official preparation of this name 
is an alcoholic solution of ethyl nitrite, C 2 H 5 N0 2 , yielding, when 
freshly made, not less than eleven times it own volume of nitric 
oxide gas. 

In the pharmacopceial process of manufacture the first step is the 
preparation of ethyl nitrite by acting on a solution of sodium nitrite 
with sulphuric acid in the presence of alcohol ; the nitrous acid lib- 
erated attacks the alcohol, forming ethvl nitrite, which distils over, 
and water, thus C 2 H 5 OH+HNO 2 =C 2 *H 5 N0 2 +H 2 0. 

The ethereal distillate is next washed with ice-cold water and after- 
ward with ice-cold sodium carbonate solution, then well shaken with 
anhydrous potassium carbonate for the purpose of dehydration, and 

37 



578 



PHARMACEUTICAL CHEMISTRY. 



finally filtered into sufficient deodorized alcohol to make the weight 
of the finished solution equal to twenty-two times the weight of 
purified ethyl nitrite obtained. The advantages of this process over 
those formerly employed consist in the absence of nitric acid and 
consequent less production of aldehyde and in the better control of 
action by the use of sodium nitrite in solution and diluted sulphuric 
acid. The reaction occurring can be illustrated by the following 
equation : 2NaJST0 2 +2C 2 H 5 OH + H 2 S0 4 = 2C 2 H 5 N0 2 +Na 2 SO 4 + 
H 2 S0 4 . 

Some years ago a method was suggested by Messrs. Dunstan & 
Dymond in England, for preparing ethyl nitrite from sodium nitrite, 
without the aid of heat, by introducing a well-cooled mixture of 



Fig. 287. 



Fig. 288. 




30 

40 
50 
60 
70 
80 
90 
100 




30 

ILJ20 
Z-10 



10 
_J20 

30 
40 
50 
GO 
70 
^0 
00 
100 



Lunge's Nitrometer. 




Curtman's Nitrometer. 



sulphuric acid, alcohol, and water, by means of a long thistle tube, 
to the bottom of a narrow glass vessel containing a strong solution 
of sodium nitrite and surrounded with ice and salt. The newly- 
formed ethyl nitrite separates rapidly and floats as a yellowish layer 
on the saline solution, whence it can be removed by decantation or 
with a siphon and purified as in the official process. The product 



ALCOHOL AND ITS DERIVATIVES. 579 

is said to be far less contaminated than when made by distillation, 
and the process is expeditions and convenient. 

By some pharmacists spirit of nitrous ether is made by mixing 
ethyl nitrite, purchased on the market, with alcohol, but it should be 
borne in mind that ethyl nitrite readily deteriorates by keeping. If 
the ethyl nitrite be of good quality and freshly prepared, this is a 
convenient plan for preparing small quantities of the official solu- 
tion. 

The Pharmacopoeia directs the assay of spirit of nitrous ether to be 
made by gasometric estimation, the nitric oxide obtainable from a 
giveu volume of the spirit being evolved and measured over a satu- 
rated solution of table salt in a graduated tube or nitrometer (see 
Figs. 287 and 288) ; full details of the process are given on pages 
509 and 510 of the Pharmacopoeia. The equation, C.,H 5 N0 2 + 
KI + H 2 S0 4 = C 2 H 5 OH + KHS0 4 + I + NO, shows "that 74.87 
Gm. of pure ethyl nitrite will yield 29.97 Gm. of nitric oxide 
measuring at 0° C. (82° F.) 22320 Cc; hence each Cc. of NO gas 
at 0° C. (32° F.) must correspond to 0.0033543 + Gm. of C 2 H 5 X0 2 , 
for 74.87 -*- 22320 = 0.0033543 +. As already stated in connec- 
tion with the valuation of sodium nitrite, on page 450, 1 Cc. NO 
gas at 15° C. (59° F.) weighs 0.0012727 Gm. and at 25° C. (77° 
F.), 0.00123 Gm.; therefore, since 29.97 Gm. of nitric oxide gas 
represent 74.87 Gm. of ethvl nitrite, each Cc. of the gas at 25° C. 
(77° F.) must correspond to 0.003072 + Gm. of true C 2 H 5 N0 2 ; 
for 29.97 : 74.87 : : 0.00123 : 0.003072 +. The quantity of ethyl 
nitrite correspond iug to each Cc. of nitric oxide gas at any other 
temperature can be readilv ascertained by dividing 0.001342656, 
the weight of 1 Cc. NO gas at 0° C. (32° F.) by the expansion of 
1 Cc. of a gas for the given temperature (see page 510 U. S. Ph.)? 
multiplying the quotient so obtained by 74.87 and dividing the pro- 
duct by 29.97. 

When strict accuracy is desired in gasometric estimations it be- 
comes necessary also to make a correction of the gas volume for 
deviation from normal barometric pressure, which is 760 Mm. or 
29.87 -p inches. As the volume of all gases is inversely propor- 
tional to the pressure applied, any volume multiplied by the pressure, 
expressed in millimeters or inches and then divided by 760 or 
29.87, as the case may be, will express the true volume under 
normal pressure. Thus 50 Cc. of NO gas under 782 Mm. pressure 
will correspond to 51.44 -f- Cc. under normal pressure ; for 760 : 
782 : : 50 : 51.44 -j- . Such correction of volume for pressure must 
be applied to the expansion of 1 Cc. for the given temperature be- 
fore ascertaining the equivalent weight of ethyl nitrite, thus 1.091575 
Cc. NO gas at 25° C. (77° F.) under 782 Mm. pressure is equiva- 
lent to 1.123173 Cc. at the same temperature under normal pressure ; 
for 1.091575 multiplied by 782 and divided by 760 is equal to 
1.123173. 

Having acertained the weight of ethyl nitrite corresponding to 1 



580 PHARMACEUTICAL CHEMISTRY. 

Cc. of NO gas under the conditions existing at the time of making 
the assay, the number of Cc. of NO gas obtained from the sample 
used multiplied by such weight at once expresses the total weight 
of ethyl nitrite preseut, which multiplied by 100 aud divided by the 
weight of the sample used (ascertained by multiplying the volume 
by the specific gravity of the sample) expresses the percentage of 
true ethyl nitrite found. 

Some authorities prefer to reduce the volume of nitric oxide gas 
obtained at any given temperature and pressure direct to the corre- 
sponding volume at 0° C. (32° F.) and 760 Mm. pressure and then 
multiply the number of cubic centimeters so obtained by 0.0033543, 
the weight in grammes of ethyl nitrite corresponding to 1 Cc. NO 
gas under normal conditions, and from this product calculate the 
percentage of C 2 H 5 N0 2 in the sample, as indicated in the preceding 
paragraph. 

In the official test 5 Cc. of spirit of nitrous ether are used, which 
should yield not less thau 55 Cc. of NO gas at 25° C. (77° F.) to 
show at least 4 per ceut. of pure ethyl nitrite. At 25° C. (77° F.) 
each Cc. NO, as shown above, corresponds to 0.003072 Gm. C 2 H 5 - 
N0 2 , hence 55 Cc. represent 0.16896 Gm. If the sample of spirit 
of nitrous ether be of the average specific gravity stated in the 
Pharmacopoeia, the 5 Cc. used will weigh 4.195 Gm. for 5X0.839= 
4.195, and to ascertain the percentage of ethyl nitrite found it is nec- 
essary to multiply 0.16896 by 100 aud divide by 4.195, which yields 
4 per cent. 

Commercial spirit of nitrous ether is often of very inferior quality, 
since it is frequently kept in large carboys insecurely stoppered, and 
consequently becomes oxidized by the air and moisture. It should 
always be purchased in original packages of small size and preserved 
in a cool, dark place. The acid reaction observed in some samples of 
spirit of nitrous ether, is due to acetic acid produced by oxidation 
from the aldehyde always more or less present ; such acidity should 
invariably be neutralized by means of alkali carbonate, before dis- 
pensing the spirit in conjunction with alkali iodides, bromides, etc. 

Even under the most favorable conditions spirit of nitrous ether 
gradually deteriorates, and, if found to contain less than 3 per cent, 
of ethyl nitrite, should be condemned. Exposure to diffused day- 
light and air accelerates decomposition, hence, when purchased in 
bulk, drawn from half-filled or carelessly stoppered containers, the 
spirit is often worthless. The author has repeatedly had occasion to 
examine the spirit of nitrous ether offered for sale in bulk by job- 
bers in different parts of the country, and regrets to say that only in 
a few cases has the strength found ever approached that required by 
the Pharmacopoeia ; in some cases, less than 1 per cent, of ethyl 
nitrite was present. 

Amyl Nitkite. Under this name the Pharmacopoeia recognizes 
a liquid containing about 80 per cent, of true amyl nitrite, C 5 H n N0 2 , 



ALCOHOL AND ITS DERIVATIVES. 581 

together with variable quantities of undetermined compounds. Al- 
though not a derivative of official alcohol, this preparation may be 
conveniently considered at this point, owing to its similarity, chemi- 
cally, to the preceding solution. Amyl nitrite is an ester, or ethereal 
salt, bearing the same relation to amyl alcohol as ethyl nitrite bears 
to official or ethyl alcohol. It can be prepared by direct action of 
nitric acid on purified amyl alcohol, but is now probably altogether 
obtained by distilling a solution of sodium nitrite with amyl alcohol 
and sulphuric acid, that portion of the distillate coming over between 
95° and 100° C. (203° and 212° F.) being collected, washed with 
ice-cold sodium carbonate solution, dehydrated with anhydrous 
potassium carbonate and redistilled below 100° C. (212° F.). Ac- 
cording to the equation, 2C 5 H n OH + 2NaM) 2 -j- H 2 S0 4 = 2C 5 H U 
N0 2 + Na 2 S0 4 + 2H 2 0, 233.56 parts of amyl nitrite should be ob- 
tained from 175.62 parts of amyl alcohol, but, in practice, such is 
not the case. 

As amyl nitrite rapidly deteriorates by exposure to air and light, 
it must be kept in securely closed, small vials, in a dark place. The 
commercial article is very variable in quality, 16 samples having 
been examined in 1892 by Dr. C. O. Curtman, with results rang- 
ing from 27.14 to 93.71 per cent, of true amyl nitrite. The valua- 
tion of amyl nitrite is made gasometrically, as in the case of spirit of 
nitrous ether, the amyl nitrite being dissolved in a little alcohol 
previous to introducing it into the nitrometer. The equation, C 5 H U - 
N0 2 -f KI + H 2 SO, = C 5 H n OH + I + NO + KHSQ 4 , shows 
that 116.78 Gm. of amyl nitrite will yield 29.97 Gm. of nitric 
oxide, hence each Cc. of NO at 25° C. (77° F.), weighing 0.00123 
Gm., corresponds to 0.004792-f- Gm. of C 5 H n N0 2 . In the official 
test, 0.26 Gm. of amyl nitrite is used, which should yield nearly 
43.5 Cc. of nitric oxide at 25° C. (77° F.) ; for 80 per cent, of 0.26 
is 0.208 and 208 -r- 0.004792 = 43.4 + . 

Paraldehyde. This liquid is a polymeric form of ethylic alde- 
hyde, which latter is an oxidation product of alcohol. 

Aldehydes, chemically speaking, are derived from primary alco- 
hols, contain the characteristic group COH, and, upon further oxida- 
tion, yield acids. Ethylic or acetic aldehyde, commonly known as 
aldehyde in commerce, is a colorless, neutral liquid obtained by dis- 
tilling a mixture of alcohol, water, sulphuric acid and manganese 
dioxide or potassium dichromate ; the crude product is dissolved in 
ether and charged with ammonia gas. The resultiug crystals of 
aldehyde-ammonia, C 2 H 4 ONH 3 , are distilled with diluted sulphuric 
acid and rectified over calcium chloride. By condensation of three 
molecules of aldehyde, one of paraldehyde is formed, 3C 2 H 4 = C 6 
H 12 3 . 

The latter is usually prepared by passing gaseous hydrochloric 
acid into aldehyde at ordinary temperature until the liquid is no 
longer soluble in an equal volume of water. By repeated freezing 



582 PHARMACEUTICAL CHEMISTRY. 

and distillation the crude product is purified until it finally all vola- 
tilizes at 124° C. (355.2° F.). 

Chloroform. Formerly all chloroform was made by distilla- 
tion of alcohol with a mixture of chlorinated lime and water, and the 
British Pharmacopoeia still recommends this process, with the ad- 
dition of slaked lime. The reactions by this method are somewhat 
complicated, resulting in the formation of chloroform and calcium 
chloride and formate. The distillate is shaken with water to remove 
any undecomposed alcohol when crude chloroform separates. 

Some chloroform is also obtained commercially by treating chloral- 
hydrate with sodium hydroxide when the following reaction occurs : 
C 2 HC1 3 0.H 2 + NaOH = CHC1 3 + NaCH0 2 +H 2 0. The chloro- 
form is distilled off while sodium formate remains in aqueous solu- 
tion. 

Since 1885 nearly all the chloroform has been made from acetone, 
by distillation with chlorinated lime, it having been found to be the 
richest chloroform-yielding substance known. Acetone is extensively 
produced by destructive distillation of acetates or acetic acid (see page 
551), and, since calcium acetate is regenerated in the manufacture of 
chloroform by the acetone process the latter has proven most profit- 
able. A full description of the method and apparatus used can be 
found in the American Journal of Pharmacy, for 1889. The re- 
action occurring maybe illustrated as follows: 2C 3 H 6 + 6CaOCl 2 
=2CHCl 3 +Ca(C 2 H 3 2 ) 2 H-2Ca(OH) 2 +3CaCl 2 . The chloroform ob- 
tained by this method is quite free from the chlorinated by-products 
frequently found in that made from alcohol. 

For the purpose of purification on a commercial scale, chloroform 
is made to bubble up slowly through two successive deep layers of 
concentrated sulphuric acid, and afterward brought into intimate 
contact with anhydrous sodium carbonate for the purpose of remov- 
ing any water and acid mechanically carried over. Finally the 
chloroform is siphoned into a dry still and distilled in a water-bath 
at a temperature not exceeding 62° C. ( 142.60° F.). The same method 
slightly modified, so as to adapt it to small quantities, is recom- 
mended in the Pharmacopoeia for the treatment of chloroform not 
complying with the official requirements. The sulphuric acid de- 
stroys any organic impurities present and gradually darkens in color, 
becoming finally black. 

Absolutely pure chloroform is very unstable when exposed to air 
and diffused daylight, but if air be rigidly excluded it does not 
suffer decomposition even in direct sunlight. Experience has proven 
that the best preservative agent for chloroform is alcohol, and the 
Pharmacopoeia therefore directs the presence of from 0.6 to 1.0 per 
cent, of the latter. The chief products of decomposition of chloro- 
form are free chlorine and carbonyl chloride, COCl 2 , which are 
readily detected by the official tests, and no chloroform should be used 
for internal administration which shows any contamination. The 



ALCOHOL AXD ITS DERIVATIVES. 583 

present Pharmacopoeia recognizes but one kind of chloroform, but 
the term " purified chloroform " is still used by some manufacturers. 
The term for my 1 terchloride is sometimes applied to chloroform, 
which indicates its chemical composition, CHC1 3 , as a haloid ether ; 
it ma) r also be called trichlormethane if looked upon as methane or 
marshgas in which three hydrogen atoms have been replaced by 
chlorine. 

Bromoform or tribromomethane, CHBr 3 , is a compound analo- 
gous to chloroform. It is now chiefly obtained by the action of alkali 
hyprobromite on acetoue in place of alcohol. The reaction, resemb- 
ling that explained under chloroform, takes place also in the cold, the 
bromoform separating as a colorless very heavy liquid of 2.9 spe- 
cific gravity and boiling at 148° C. (298.4° F.). It is sparingly 
soluble in water but readily so in alcohol, and is easily decomposed by 
sunlight. Bromoform is unfit for use if colored or of an acid reaction. 

Ethyl Bromide. This liquid, also known as hydrobromic ether, 
belongs, like chloroform and bromoform, to the class of compounds 
called by chemists haloid ethers, one or more atoms of hydrogen in 
hydrocarbons or of hydroxyl in the corresponding alcohols having 
been replaced by either of the haloid elements. While not official in 
the United States and British Pharmacopoeias, it is recognized in the 
German Pharmacopoeia as cether bromatus, and is prepared by distil- 
ling a mixture of potassium bromide, alcohol, and sulphuric acid, 
washing the distillate with potassium carbonate solution and then 
water and finally rectifying over calcium chloride. The following 
equation explains its formation : C 2 H 5 OH-j-KBr-f H 2 SO^=C 2 H 5 Br 
-f- KHS0 4 -f-H 2 0. Ethyl bromide is a colorless liquid of nearly 
the same specific gravity as chloroform, but boiling at 38° or 40° C. 
(100.4°-104° F.) ; it has a neutral reaction but is readily decom- 
posed by light and air, becoming acid and dark in color. It must 
not be confounded with ethvlene bromide, C 2 H 4 Br 2 , a liquid of 2.163 
specific gravity and boiling'at 131° C. (267.8°F.). 

Chloral. It is unfortunate that the Pharmacopoeia has con- 
tinued the blunder of its predecessor by applying the term chloral, as 
the official title, to the well-known hydrate of that compound, and 
more particularly since foreign pharmacopoeias have recognized the 
proper name. True chloral is an oily liquid having the composition, 
C 2 HC1 3 0, whereas the official article is a crystalline compound of 
the same with water. 

In the manufacture of chloral, perfectly dry chlorine gas is passed 
into cold absolute alcohol as long as the former continues to be rapidly 
absorbed, after which the mixture is ^raduallv warmed up to 60°- 
70° C. (140°-158° F.) and treated "with sulphuric acid, whereby 
crude chloral is separated as a thin oily liquid, which is then rectified 
over burned lime and chalk ; the final distillate of pure chloral is 



584 PHARMACEUTICAL CHEMISTRY. 

weighed and hydrated by the addition of a calculated quantity of 
water, and the hot mass poured upon plates of glass, covered with a 
bell-glass and allowed to crystallize. 

The reactions occurring in the above process were formerly sup- 
posed to consist in the formation of aldehyde and the conversion of 
this into chloral or trichloralclehyde by the action of chlorine, as 
illustrated by the equations, C 2 H 5 OH + Cl 2 =C 2 H 4 0-f-2HCl and 
C 2 H 4 0+C1 3 =C 2 HC1 3 + 3HC1. This view is no longer tenable, 
since it has been found that chlorine brought into contact with alde- 
hyde yields trichlorbutylaldehyde, C 4 H 5 CJ 3 0, a condensation pro- 
duct, instead of chloral. According to recent authorities, the nascent 
aldehyde produced by the action of chlorine on alcohol, acts upon 
the absolute alcohol present, forming acetal and water, thus : 
2C 2 H 5 OH+C 2 H 4 0=C 2 H 4 (0C 2 H 5 ) 2 +H 2 O; the acetal is converted 
by chlorine into trichloracetal, C 2 H 4 (OC 2 H 5 ) 2 +C] 6 =C 2 HC] 3 (OC 2 H 5 ) 2 
-f-3HCl, and this is decomposed by the hydrochloric acid present into 
chloral alcoholate and ethvl chloride, thus C,HC1 3 (0C 2 H 5 ) 2 +HC1= 
C 2 HCl 3 O.C 2 H 5 OH+C 2 H 5 Cl ; finally the chloral alcoholate is decom- 
posed by sulphuric acid into chloral, ethvl sulphuric acid, and water, 
C 2 HCl 3 O.C 2 H 5 OH4-H 2 S0 4 =C 2 HCl 3 O+C 2 H 5 HSO 4 -fH 2 O. Other 
decomposition products are also formed in small quantities. 

In order to further purify the crystals of chloral hydrate, it is 
customary for manufacturers to again decompose the hydrate with 
sulphuric acid, whereby pure chloral is set free, and then rectify, re- 
hydrate, and recrystallize the product. 

Chloral hydrate should never be exposed to direct sunlight and 
its aqueous solutions, dispensed in conjunction with strongly alcoholic 
liquid, are apt to separate less soluble chloral alcoholate. When dis- 
pensed together with concrete volatile oils or phenols, the mixture 
should be thoroughly triturated until perfect solution (liquefaction) 
has been obtained. Mixed with alkalies, chloral is split up into 
chloroform and alkali formate. (See page 582.) 

Chloral has yielded a number of derivative products which are 
used to some extent. The most prominent of these is chloralamide, 
C 2 HCl 3 O.CHONH 2 , made by interaction between anhydrous chloral 
and formamide, CHONH 2 (a colorless oily liquid produced by dry 
distillation of urea and ammonium formate), at about 140° C. 
(284° F.). It is recognized in the German Pharmacopoeia as chlora- 
lum formamidaium, and occurs in white, lustrous crystals which are 
slowly soluble in cold water but are decomposed by water heated to 
60° C. (140° F.). Chloralamide is used as a hypnotic, and must not 
be confounded with chloralimide obtained by the action of heat on 
chloral-ammonium. 

Other compounds, such as hypnal, a compound of chloral and anti- 
pyrine, — somnal, a compound of chloral, urethane, and alcohol — 
ural or uralium, chloral-urethane — and others are less important. 
(A full account of these may be found in the National Dispensatory, 
fifth edition, p. 455.) 



ALCOHOL AND ITS DERIVATIVES. 585 

Closely allied to the official chloral is butyl-chloral hydrate, which 
is recognized in the British Pharmacopoeia, and is, in commerce, often, al- 
though wrongly, called croton-chloral hydrate. It is prepared from eth- 
ylic aldehyde, by acting upon it with chlorine, at a low temperature — 
— 10° C. (14° F.) ; the mixture is finally subjected to fractional distil- 
lation until a product boiliDg uniformly between 163° and 165° C. 
(325.4° and 329° F.)is obtained, consisting of trichlorbutylaldehyde 
or butyl-chloral, which is then converted into the crystalline hydrous 
variety by addition of water. Butyl-chloral hydrate dissolves spar- 
ingly in cold water, but freely in hot water, alcohol, and glycerin. 
It differs from chloral hydrate by not yielding chloroform with 
alkalies but instead dichlorallylene, C 3 H 2 C1 2 . 

Iodofoem. This compound may be obtained from alcohol or 
acetone, by the action of iodine in the presence of alkali hydroxides 
or carbonates. For many years only alcohol was used and either 
Bouchardat's or Filhol's process employed. The former consists in 
heating iodine, potassium bicarbonate, alcohol, and water, in a long- 
neck flask, to between 60° and 80° C. (140° and 176° F.), until the 
color has disappeared, then adding small portions of iodine as long as 
these are taken up and decolorized ; the mixture is finally set aside 
for twenty-four hours and the crystals collected on a filter. About 
one-third of the iodine is recovered as iodoform, the remainder form- 
ing potassium iodide. 

Filhol's process insures a much larger yield. Iodine is added in 
small portions to a warm mixture of sodium carbonate, w r ater, and 
alcohol, and, after cooling, the crystals are collected ; the filtrate is 
again warmed, some alkali carbonate added and a rapid current of 
chlorine passed through the liquid as long as iodoform is separated, 
which is again collected and the filtrate made to yield more iodoform 
by repeating the treatment. The formation of iodoform may be illus- 
trated by the following equations C 2 H 5 OH + I 8 — t)KHC0 3 =CHI 3 
+ 5KI + KCH0 2 + 6C0 2 -f5H 2 0, alkali formate being probably al- 
ways produced together perhaps with ethyl iodide, acetic ether, and 
other compounds. The results appear to be greatly influenced by the 
relative proportions of the materials used and the temperature em- 
ployed. 

Since 1889 the process of Sulliot and Raynaud has been largely 
used, by means of which iodoform of unusual purity is obtained. 
A solution of fifty parts of sodium or potassium iodide (in France 
derived from the ash of sea- weed) is mixed with six parts of acetone 
and a solution of tw T o parts of caustic soda iu 1000 parts of water ; 
a dilute solution of sodium hypochlorite is added, drop by drop, as 
long as iodoform is produced, the yield being about the theoretical 
quantitv according to the equation, 3NaI + 3NaC10 — C 3 H 6 0==CHI 3 
+ 3XaCl-hKaC 2 H 3 2 4-2XaOH. 

In Germany iodoform has also been made by subjecting a solution 
of fifty parts of potassium iodide in 300 parts of water and thirty 



586 PHARMACEUTICAL CHEMISTRY. 

parts of alcohol to electrolysis while a constant current of carbon 
dioxide is being passed into the liquid. 

During the past ten years several substitutes for iodoform have 
been introduced, but in spite of the persistent unpleasaut odor of the 
latter its use by physicians still surpasses that of the proposed sub- 
stitutes, of which the two best known are iodol and aristol. Iodol is 
chemically tetraiodopyrrol, C 4 T 4 NH, obtained by the interaction of 
iodine and pyrrol (a weak base found in coal tar) in alcoholic solu- 
tion ; it falls as a yellowish, flocculeut precipitate, upou the addition 
of water and contains about 89 per cent, of iodine. Aristol, 
also known as annidalin, is chemically dithymoldiiodide, C 20 H 24 O 2 I 2 , 
and is prepared by adding a strong solution of thymol in sodium 
hydroxide solution, with constant stirring and at an ordinary tem- 
perature, to a strong solution of iodine and potassium iodide in 
water ; aristol is formed as a dark brownish-red precipitate, which is 
subsequently washed with water and dried. 

Other compounds which have been recommended as substitutes for 
iodoform are europhen, or diisobutylorthocresol-diiodide, an amor- 
phous yellow powder, sozoidol or sozoiodolic acid and its salts, occur- 
ring in crystalline form, sulphamniol or thioxydiphenylamine, a 
yellow insoluble powder, losophaue or triiodometacresol, odorless 
and colorless crystals containing nearly 80 per cent, of iodine. The 
advantage claimed for some of these is the absence of color and odor ; 
a full account of them can be found in the National Dispensatory, 
fifth edition, pp. 879 and 880. 

Among the non-official alcohol derivatives may be mentioned the 
following : 

Bromal. CHBrO. This compound resembles chloral in its 
chemical nature, and, like it, forms a hydrate and an alcoholate. It 
is prepared, like chloral, from absolute alcohol, by the action of bro- 
mine. With alkali hydroxides bromal forms bromoform and alkali 
formate. It must not be confounded with bromol, which is tri- 
bromophenol. (See page 558.) 

Urethane. While in chemistry the term urethane is applied to 
all ethers of carbamic acid, in pharmacy and medicine it is restricted 
to one compound, namely, ethyl urethane or ethylcarbamate, 
CONH 2 OC 2 H 5 . It can be obtained in several ways, but for medicinal 
use is prepared by heating in a sealed tube a mixture of urea nitrate 
and alcohol for several hours at a temperature of 120°-130° C. 
(248° 266° F.); the resulting crystalline mass is dissolved in water 
and shaken with ether, which latter extracts the urethane and yields 
it in crystals, upon distillation, which may be further purified by re- 
crystallization from water. Phenyl urethane is known in commerce 
as euphorine. 



ALCOHOL AND ITS DERIVATIVES. 587 

Sulphonal. This is the copyrighted Dame applied to a definite 
chemical compound and recognized in the British and German Phar- 
macopoeias. Its chemical formula, (CH 3 ) 2 C(S0 2 C 2 H 5 ) 2 , shows it to 
be diethylsulphonyl-dimethyl methane. Sulphonal is prepared by 
oxidation of mercaptol with potassium permanganate and purified by 
recrystallization from water or alcohol. (Mercaptol is an oily liquid 
obtained by passing dry hydrochloric acid gas into a mixture of two 
parts of anhydrous ethyl hydrosulphide or mercaptan and one part 
of anhydrous acetone.) 

Trioxal is diethylsulphonyl-methylethylmethane, and is prepared 
exactly like sulphonal except that methyl ethyl ketone is used in 
place of acetone in the manufacture of mercaptol ; if diethyl ketone 
be used in place of acetone, another compound known as Tetroxal 
is obtained. All three compounds occur in the form of colorless 
crystals and are sparingly soluble in cold water. 



CHAPTEK LYI. 

FATS AND FIXED OILS. 

The physical properties of these compounds have already been 
considered on pages 186-195. Chemically they belong to the class 
of esters, or ethereal salts, being readily convertible into the re- 
spective acids and alcohols by means of alkali hydroxides. With a 
few exceptions, the basylons radical is the same for all fats and fixed 
oils, whether obtained from the vegetable or animal kingdom, namely, 
glyceryl or propenyl, C 3 H 5 , a trivalent group derived from the hy- 
drocarbon propane, C 3 H 8 , the alcohol or hydroxide of which is 
glycerin or propenyl alcohol, C 3 H 5 (OH) 3 ; other bases obtainable 
from fats are cholesterin, myricin, cerotin, cetin, etc. The acid radi- 
cals found in fats are many, the chief ones being oleic, palmitic, stearic, 
lauric, arachic, erucic, and myristic acids, varying from one to 
three or more in number for a single fat or fixed oil. 

The ordinary fats and oils used in pharmacy consist, for the most 
part, of two or three compound ethers, to which the names olein, 
palmitin, and stearin have been given ; of these, olein, being always 
liquid, naturally forms the chief constituent of fixed oils, while pal- 
mitin and stearin, being solid at ordinary temperatures, by their 
presence determine the firmer consistence of solid fats. All three are 
fatty acid esters of glyceryl, known respectively to chemists as gly- 
ceryl trioleate, C 3 H 5 (C 18 H 33 2 ) 3 , glyceryl tripalmitate,C 3 H 5 (C 16 H 31 2 ) 3 , 
and glyceryl tristearate, C 3 H 5 (C 18 H 35 2 ) 3 ; the names glycerides of 
oleic, palmitic, and stearic acid are also applied to them. The 
oleic acid derived from different oils, not having a uniform composi- 
tion and properties, specific names are employed to distinguish the 
respective glycerides ; thus, olein, C 3 H 5 (C 18 H 33 2 ) 3 , linolein, 
C 3 H 6 (C 18 H 31 2 ) 3 , and physetolein, C 3 H 5 (C 18 H 29 2 ) 3 ; the first named 
occurs both in animal and vegetable fats, the second only in veg- 
etable fats, while the third is confined to animal fats, chiefly fish oil, 
seal oil, etc. 

The following true fats, recognized in the Pharmacopoeia, are 
mixtures of glyceryl esters : 

Animal Fats. Lard, composed of about 60 per cent, of olein 
and 40 per cent, of a mixture of stearin and palmitin. Lard oil is 
almost pure olein with small and varying proportions of palmitin and 
stearin, dependent upon the care with which the oil has been ex- 
pressed. Suet consists of about 75 or 80 per cent, of stearin and 



FATS AND FIXED OILS. 589 

palmitin and 20 or 25 per cent, of olein. Codliver oil contains in 
its crude state about 70 per cent, of physetolein, 25 per cent, of 
palmitin together with small quantities of stearin and other glycer- 
ides ; its acid character is due to the presence of free fatty acids. It 
is said also to contain organic compounds of iodine, bromine, phos- 
phorus and sulphur, as well as trimethylamine, asellin, C 25 ,H 34 N 4 ?, 
morrhuin, C 19 H 27 N 3 ?, and morrhuic acid, C 9 H 13 N0 3 ? Morrhuol, 
said to represent the active virtues of codliver oil, is obtained by 
treating the latter with 90 per cent, alcohol and distilling the liquid 
after filtration ; it constitutes the oily residue left in the still, has a 
disagreeable odor and a sharp, bitter taste.' 

Vegetable Fats. Almond oil (expressed) is probably the purest 
form of olein, containing only very small quantities of the esters of 
linolic and the solid fatty acids, hence it can be cooled to near — 20° C. 
( — 4° F.) without congealing. Castor oil consists chiefly of ricin- 
olein, C 3 H 5 (0 18 H 33 O 3 ) 3 , which differs from olein in being the glyceride 
of an acid containing in each molecule one more oxygen atom than 
oleic acid ; small quantities of stearin are also present. It differs 
from other fixed oils in being readily soluble in alcohol and insoluble 
in benzin, petroleum, and paraffin oils. Cottonseed oil is a mixture 
of olein, palmitin, and linolein ; it contains also a small proportion 
of a non-saponifiable body. In its crude state the oil contains albu- 
minous and resinous matter, to which latter the dark color is due. 
Croton oil contains olein, palmitin, stearin, and the glycerides of a 
number of other fatty acids. The vesicating and purgative action of 
croton oil is, according to the latest investigations of Kobert, due to 
crotonolic acid, which exists in the oil both in the free state and as a 
glyceride and can be extracted by means of alcohol. Linseed oil, 
when pure, consists of 80 or 90 per cent, of linolein, the balance 
being made up of stearin, palmitin, olein, etc. Its property of ab- 
sorbing oxygen and increasing in weight is explained elsewhere. Olive 
oil is a mixture of about 70 per cent, of olein, 5 per cent, of linolein, 
and 25 per cent, of palmitin and arachin, the latter two glycerides 
being present in greater proportion in the lower grades of the oil. 
The green color is due to chlorophyll in solution. Sesame oil con- 
tains olein, palmitin, and stearin. Oil of theobroma, or cacao butter, 
is composed of the glycerides of oleic, palmitic, stearic, lauric, and 
arachic acids. 

Among the fats used in pharmacy which do not contain the radi- 
cal glyceryl, the following may be named : Beeswax, which consists 
of myricyl palmitate, C 30 H 61 .C 16 H 31 O 2 , and free cerotic acid, 
HC 27 H 23 2 , with small quantities of free melissic acid. Spermaceti 
is chiefly cetyl palmitate, C 16 H 33 C 16 H 31 27 , which, during the life of 
the sperm whale, is held in solution in sperm oil or cetinelain. 
Lanolin is a mixture of various compound ethers of cholesterin and 
isocholesterin, C 27 H 45 OH, the official article containing also 30 per 



590 PHARMACEUTICAL CHEMISTRY. 

cent, of water ; the cholesterol esters cannot be saponified by boiling 
with an aqueous solution of potassa, hence they can be readily sep- 
arated from other fats and free fatty acids with which they are 
associated in the grease of sheep's wool. Cholesterin fats are easily 
distinguished from glycerin fats by the appearance of a pink color, 
gradually chaugiug to green or blue, when concentrated sulphuric 
acid is allowed to drop slowly into a solution of 0.1 Grin, of the fat 
(lanolin) in 3.5 Cc. of acetic anhydride, (C 2 H 3 ) 2 0; fatty acid glycer- 
ides do uot show this color reaction. 

When absolutely pure, fats and fixed oils are without action on 
litmus, but in the presence of air, light and moisture, decomposition 
and oxidation gradually ensue, an unpleasant odor, due to the forma- 
tion of volatile products, and an acid reaction being observed. Fats 
are not affected by a temperature of 100° C. (212 F.) but, at 250° C. 
(482° F.), they are decomposed, various volatile products being 
formed, among which is an irritating, odorous substance, called acro- 
lein, which, chemically, is allyl aldehyde, C 3 H 4 0, and is derived 
from the decomposition of the glycerin present in fats. 

The division of fixed oils into drying and non-drying oils has 
already been mentioned on page 187 ; to the first class belongs lin- 
seed oil, while olive oil and expressed oil of almond are representa- 
tives of the second class. A third class might be named, embracing 
those oils which partake of some of the properties of both the drying 
and non-drying oils ; this class includes castor oil, cottonseed oil, and 
sesame oil. This difference in their behavior when exposed to air, is 
due to difference in chemical composition, drying oils being glycer- 
ides of linoleic acid, C 16 H 28 2 , which, upon exposure to air, absorb 
oxygen and are converted into oxylinolein, C 32 H 54 O u , or linoxin. 
Recent investigations have shown linoleic acid to be a mixture of 
variable proportions of three other acids beside oleic acid, which 
former are alone concerned in the gradual solidification of drying 
oils. The smaller the proportion of oleic acid present in drying oils, 
the more rapidly and thoroughly will the oil solidify upon exposure; 
this explains why oils belonging to the same group with cottonseed 
oil, dry so much more slowly and imperfectly than the members of 
the linseed oil group. The glyceride of oleic acid present in drying 
oils behaves like that of the non-drying oils, but decomposition is 
probably estopped by the formation of the other oxidation products ; 
hence the unpleasant odor and acidity before mentioned are not ob- 
servable in true drying oils. 

Non-drying oils, consisting chiefly of the glyceride of oleic acid, 
with varying proportions of palmitin, upon exposure to air, appear 
to absorb water and split up into free oleic (and palmitic) acid and 
glycerin, the latter being gradually oxidized into carbon dioxide and 
water, and thus disappearing. The oleic acid absorbs oxygen and is 
gradually converted into oxystearic acid and finally into volatile 
odorous acids, such as capronic, valerianic, etc. This process of de- 
composition is termed rancidification and explains the condition 



FATS AND FIXED OILS. 591 

termed rancidity, noticed in old and carelessly preserved fats and 
fixed oils. By some it is thought that the change is superinduced 
by the presence of mucilaginous or albuminous matter in the fat, 
acting as a ferment under the influence of light, air and moisture. 
Rancid fats, therefore, always contain free acid and yield less gly- 
cerin than sweet fats, when saponified. 

In the chemical examination of fats and fixed oils for adultera- 
tions, etc., two reactions are especially employed by analysts, 
namely : that with potassium hydroxide and that with iodine. In 
the first case 1 or 2 Gm. of the fat or oil are boiled with a definite 
volume, 25 Cc, of alcoholic solution of potassium hydroxide, of known 
strength, in a flask in a water-bath until saponification is complete, 
usually about 15 minutes, and an excess of alkali remains ; the ex- 
cessive alkali is determined volumetrically with deci or semi-normal 
acid and thus the quantity of alkali used for saponifying the fat ascer- 
tained ; from this, the number of milligrammes of potassium hydrox- 
ide required by one gramme of any fat or fixed oil is calculated, 
which is called Koettsdorfer's saponification factor of that particu- 
lar fat or oil. 

The iodine test depends upon the fact that fats are capable of com- 
bining with varying quantities of iodine and forming colorless addi- 
tion products under certain favorable conditions. Two solutions are 
used for this test, which is known as HubPs iodine test, namely one, 
consisting of 5 Gm. of iodine in 100 Cc. of 95 per cent, alcohol, and 
another consisting of 6 Gm. of pure mercuric chloride in 100 Cc. of 
95 per cent, alcohol. Equal volumes of the two solutions are mixed 
and allowed to stand for twenty- four hours in a well-closed bottle, after 
which the iodine value of the mixture is determined by titration with 
decinormal sodium thiosulphate solution. The fats or fixed oils are 
then tested at once, as follows : 0.2 Gm. of drying oils, 0.4 Gm. of non- 
drying oils, or 0.8 Gm. of solid fats are weighed into a 500 Cc. flask 
and dissolved in 10 Cc. of chloroform, after which 25 Cc, or in the 
case of drying oils, 40-60 Cc, of the above iodine mixture are added ; 
if after agitation the liquid is not clear a little more chloroform must 
be added. The flask is tightly closed and set aside for two hours, 
when the mixture should still remain highly colored, otherwise 10 or 
15 Cc. more of the iodine mixture are added and the flask set aside 
for two hours more. About 20 Cc. of a 10 per cent, aqueous solution 
of potassium iodide are now added, as also 150 Cc. of water and 
decinormal sodium thiosulphate added from a burette, with frequent 
agitation, until both the aqueous and chloroformic layers are decolor- 
ized, using starch mucilage as an indicator toward the end. Having 
thus ascertained by difference the amount of iodine actually absorbed 
by the fat, the iodine number, as the amount of iodine absorbed by 
100 Gm. of any fat or oil is usually termed, can readily be calculated 
by the rule of three, thus if 0.4 Gm. of a fixed oil have absorbed or 
combined with 0.3 Gm. of iodine the iodine number of that oil will 
be 75 for 0.4 : 0.3 : : 100 : 75. 



592 PHARMACEUTICAL CHEMISTRY. 

The following table shows the behavior, when pure, of some of the 
leading fixed oils used in pharmacy toward potassium hydroxide and 
iodine. The variations are due to age and other unavoidable condi- 
tions : 

Name. Saponification Factor. Iodine Number. 

Expressed Oil of Almond . . 187.9-195.4 97.5-98.9 

Olive Oil 185.2-196.0 81.6- 84.5 

Castor Oil 176.0-181.5 86.6- 93.9 

Sesame Oil 190.0-194.6 108.9-111.4 

Cottonseed Oil . . . . 191.0-210.5 110.9-115.7 

Linseed Oil 189.0-195.2 155.2-178.5 

The action of acids on fats and fixed oils varies considerably ; 
thus, strong hydrochloric acid has no effect upon them, as als o 
cold diluted nitric acid and cold or hot diluted sulphuric acid. 
Nitrous acid, as well as warm nitric acid, converts olein into elaidin, 
a compound isomeric with it, but of firm consistence. Strong 
sulphuric acid decomposes fats slowly in the cold and rapidly with 
the aid of heat, forming sulpho-compouuds of the fatty acids, as 
well as of the glycerin. If concentrated sulphuric acid be added 
to almond or olive oil and the mixture be kept at a temperature 
below 50° C. (122° F.), sulpho-oleic and glyceryl sulphuric acids 
will be formed, HS0 3 C 18 H 33 2 and C 3 H 5 (HS0 4 ) 3 j if castor oil be 
used, sulphoricinoleic acid will be produced. The glycerylsulphuric 
acid, upon addition of water, is again converted into glycerin and 
water, and can thus be removed ; the sulpho-oleic acid, having been 
purified by washiug with salt solution, can be combined with alkali 
hydroxides, yielding water miscible sulpho-oleates, which on account 
of their absorbability have been recommended as vehicles for oint- 
ments, under the names oleite, poly solve, etc. (see page 371). 

Decomposition of fats can also be effected by superheated steam, 
which fact is utilized in the manufacture of glycerin on a large scale, 
as already explained on page 196. 

Saponification. Alkali hydroxides and moist metallic oxides, 
in the cold, only partly decompose fats and fixed oils, forming emul- 
sions with them, as shown in the case of the official ammonia and 
lime liniments, but, at boiling temperature, complete dissociation is 
effected, the fatty acids combining with the metallic base, while 
glycerin is liberated. The new compounds thus obtained are known 
as soap, and the process is termed saponification ; the character of the 
soap depends upon the particular hydroxide employed, soda invari- 
ably forming hard soap while potassa and ammonia form soft soap. 
The process of saponification may be illustrated by the following 
equation, C 3 H 5 (C 18 H 33 2 ) 3 + 3NaOH = 3NaC 18 H 33 2 + C 3 H 5 (OH) 3 , 
which represents the manufacture of hard soap from olive oil. 

In the manufacture of soap it is customary to add the alkali solu- 
tion in slight excess to the fat, in order to insure complete decom- 
position of the latter, the excess remaining in solution. Boiling of 



FATS AND FIXED OILS. 593 

the mixture is continued until it becomes transparent and somewhat 
tenacious, showing that no uncombined fat remains ; this is necessary, 
as the decomposition of the fat is gradual and the newly formed 
soap serves as an emulsifying agent for the fat. As the process nears 
completion iridescent bubbles are seen to rise on the surface, consist- 
ing of soap solution. Finally common salt is added to the finished 
solution, whereby the soap is precipitated and can then be drained 
and allowed to dry in suitable moulds. This explains the fact that 
ordinary soap will cause no lather with sea water, a special soap 
made with cocoa-nut oil or resin, and known as marine soap being 
preferable for this purpose, since it is soluble in the solution of salt. 
Since all fats contain some palmitiu or stearin (even the fixed oils), 
the consistence of the soap will depend in part upon the proportion 
of solid fats present, being firmest in soaps made partly with stearin 
fats, such as suet, tallow, etc. 

The term saponification is also used to express the decomposition 
of fats aud fixed oils by water with the aid of superheated steam, 
which results in the liberation of the fatty acids and glycerin, as in 
the case of tallow or suet, thus : C 3 H 5 (C 18 II 35 2 ) 3 -f- 3H 2 = 
3HC 18 H 35 2 -f-C 3 H 5 (OH)3. Chemists, not confining the process to 
the glycerides of fatty acids, further apply the term to the resolution 
of all compound ethers by an alkali into the respective acids and 
alcohols, which is often practised in connection with the determin- 
ation of certain constituents of volatile oils. The action of potassa 
on aldehyde, resulting in the formation of aldehyde- resin, has also 
sometimes, but erroneously, been called saponification. In pharmacy, 
the term soap is always restricted to the alkali salts of fatty acids, 
obtained by treatment of a fat or fixed oil with a boiling solution of 
soda or potassa, which are soluble in water ; the name oleate or 
plaster is more properly applied to those soaps which are insoluble 
in water or alcohol and are made with the oxides of the earths or 
heavy metals. Soap made wholly from animal fat is but sparingly 
soluble in cold alcohol and therefore to be preferred for the prepar- 
ation of solid opodeldoc and similar firm liniments. 

Medicated Soaps. While soaps intended simply as detergents, 
may, without detriment, contain a very slight excess of alkali, it is 
desirable, when medication of the soap is intended, that prior to its 
application, a perfectly neutral substance be employed ; it has, in 
fact, been found that soap containing uncombined fat is even prefer- 
able to neutral or normal soap, for not only does it render the skin 
softer but reaction between the soap and any medicinal agent added 
is also thereby avoided or at least retarded. Such soaps, containing 
an excess of fat, are known as u superfatted soaps " and have been 
largely used for the past ten years. In preparing them it is custom- 
ary to add an excess of 3 or 5 per cent, of fat or fixed oil in the be- 
ginning of the operation, which then remains intimately mixed with 
the newly formed soap. In a few cases the excess of fat has been 

38 



594 PHARMACEUTICAL CHEMISTRY. 

incorporated with the freshly made, neutral soap while yet in a soft, 
pasty condition. Both olive oil and lanolin are used in the manu- 
facture of superfatted soaps, having been found preferable to all 
other fats in their action on the skin and toward chemicals. 

In the manufacture of medicated soaps the plan followed is iden- 
tical with that prescribed on page 373 for ointments. The medicinal 
agent is first intimately mixed (either in the form of solution or im- 
palpably fine powder) with a small portion of the superfatted soap, 
by means of suitable apparatus, which mixture is then added to such 
a further quantity of the same vehicle as may be necessary to estab- 
lish the required percentage strength of the finished product. Among 
the various medications of superfatted soaps are tar 5 per cent., sul- 
phur 10 per cent., salicylic acid 5 per cent., borax 5 per cent., car- 
bolic acid 5 and 10 per cent., corrosive sublimate -^ and J per cent., 
camphor 5 per cent., and others. 

Official Soaps. The Pharmacopoeia recognizes two varieties 
of soap, one by the general name soap (Latin, sapo) and the other 
by the general name soft soap (Latin, sapo mollis). The first is in- 
tended to be a hard soap made from olive oil and soda, as already 
explained. When fresh, or if kept in a damp cellar, it usually con- 
tains a large proportion of water, most of which is lost by drying 
in a warm, airy room and all of which can be expelled at a temper- 
ature of 110° C. (230° F.). White castile soap, the kind officially 
recognized, usually contains a slight excess of alkali, which should 
not, however, exceed 1 per cent, of sodium carbonate or 0.25 per 
cent, of sodium hydroxide, as indicated by the official test with ^ 
oxalic acid solution. The Pharmacopoeia also demands the absence 
of more than 2 per cent, of matter insoluble in water. 

The soft soap of the Pharmacopoeia is directed to be made by the 
action of potassa on linseed oil. Commercially, it is generally known 
as green soap, which was formerly also the official title; the color is, 
however, by no means green, being yellowish-brown. On account of 
the unsightly appearance and disagreeable odor of the official prepar- 
ation, the use of olive in place of linseed oil has been recommended, 
yielding a more satisfactory product. The value of the official soft 
soap is partly due to its greater alkalinity. In the German Pharma- 
copoeia this soap is known as sapo kalinus. 

Lead plaster is sometimes spoken of as lead soap, and, in its manu- 
facture, a process similar to that used for the official hard soap is 
employed, finely divided lead oxide being allowed to act upon heated 
olive oil, in the presence of water, forming lead oleate (oleopalmi- 
tate) and liberating glycerin, which latter is removed by subsequent 
washing with warm water. The use of water is essential, as it not 
only keeps the temperature down to that of boiling water, thus pre- 
venting decomposition of the olive oil at a higher heat, but also very 
materially aids in the reaction between the oil and lead oxide, as 
shown by the equation, 2C 3 H 5 (C 18 H3 3 2 )3 + 3PbO + 3H 2 = 



FATS AND FIXED OILS. 595 

3Pb(C ls H330 2 ) 2 - 2C 3 H 5 (OH) 3 . The finished product, which is a 
normal lead oleate mixed with small quantities of lead palmitate, 
owing to the pal mi tin in the olive oil, should not be sticky or greasy 
to the touch, and should dissolve completely in warm oil or turpen- 
tine, showiug the absence of free oil and uncombined lead oxide. 

The name diachylon plaster, which is still applied to lead plaster, 
was given to it during the middle ages, wdien mucilage of linseed, 
althaea and similar substauces, was added to the mixture before 
heating, with the view of retardiug the evaporation of water and 
possibly also to increase the plastic condition of the finished product. 
The term diachylon is derived from the Greek words oca, through 
or with, and /^/oc, juice. 

Glyceric. As already stated, the basylous radical found in 
nearly all fats and fixed oils is glyceryl, the hydroxide of which is 
glycerin, C 3 H 5 (OH) 3 , a triatomic alcohol. Its manufacture, on a com- 
mercial scale, has been explained on page 195. While glycerin is 
unaffected by cold nitric or sulphuric acid separately, a mixture of 
the two acids forms with it a definite chemical compound, glyceryl 
or propenyl trinitrate, C 3 H 5 (X0 3 ) 3 , commonly but wrongly called 
nitroglycerin aud also known as glonoin and trinitrin. 

Glyceryl trinitrate is prepared by adding a mixture of 100 parts 
of anhydrous glycerin and 3 parts of sulphuric acid spec. grav. 
1.835, gradually and in small portions at a time, to a well-chilled 
mixture of 280 parts of nitric acid spec. grav. 1.5, and 300 parts of 
sulphuric acid spec. grav. 1.835, the vessel being kept surrounded 
by ice. This mixture is afterward poured into six times its volume 
of cold water, washed free from acid, and finally dried over sulphuric 
acid. The reaction may be illustrated as follows : C 3 H 5 (OH) 3 -f- 
3HNO s -f H 2 S0 4 = QH 5 (X0 3 ) 3 -f 3H 2 + H 2 S0 4 , the sulphuric 
acid simply serving to withdraw the water eliminated in the forma- 
tion of the compound ether. 

The product is a slightly yellowish, oily liquid, insoluble in water 
but soluble in alcohol. It has a sweet, aromatic taste, and is very 
poisonous. 

In the form of al per cent, alcoholic solution, glyceryl trinitrate is 
recognized, in the Pharmacopoeia, as Spirit of Glonoin ; tablet tritur- 
ates and chocolate tablets containing 0.00065 and 0.0013 Gm. (y-g-g- 
and -^ grain) of glonoin each are also used by physicians ; mixed 
w T ith three parts of infusorial earth (kieselguhr), it constitutes dyna- 
mite, a well-known blasting agent. 

Petroleum Products. Pharmaceutical^ closely allied to the 
fats, but chemically entirely distinct are those mixtures of hydro- 
carbons of the paraffin series obtained by purification of the resid- 
uum from the distillation of American petroleum. They are recog- 
nized in the Pharmacopoeia by the name " Petrolatum," in three 
varieties, as liquid, soft, and hard ; a still firmer variety is recognized 



596 PHARMACEUTICAL CHEMISTRY. 

in the British and German Pharmacopoeias as "hard paraffin." 
These substances are fat-like in appearance and extensively employed 
as vehicles for the application of numerous remedial agents; commer- 
cially they are known as vaseline, cosmoline, albolene, petrolina, etc. 

The existence of petroleum in the earth has not as yet been satis- 
factorily explained ; several theories have been advanced, the most 
acceptable of which is that petroleum is the result of dissociation of 
large quantities of fatty matter (derived from marine animals), while 
under long-continued pressure, at a moderate temperature, with en- 
tire exclusion of air. 

American petroleum consists of a mixture of hydrocarbons of the 
fatty or marsh gas series from methane upward to those richest in 
carbon, together with small and varying proportions of aromatic 
hydrocarbons. Upon subjecting the crude petroleum to a refining 
process by fractional distillation, benzin or naphtha, illuminating 
oils, and a residuum largely composed of paraffins are obtained. All 
fractious are then further purified by treatment with sulphuric acid 
and subsequently with alkalies, after which they are subjected to 
further fractional distillation. The benzin recognized in the Phar- 
macopoeia also as petroleum benzin or petroleum ether, is collected be- 
tween 50° and 60° C. (122° and 140° F.) and should be free from 
sulphur compounds. Its chief components are the hydrocarbons, 
pentane (C 5 H 12 ), and hexane (C 6 H 14 ). Official benzin is a valuable 
solvent for fats, caoutchouc, and some alkaloids, and, as such, is exten- 
sively employed ; it must not be confounded with benzene, C 6 H 6 , a coal 
tar derivative (see page 555). Benzin is highly inflammable, and its 
vapor, like that of ether, is explosive when mixed with air and ignited. 

Upon distilling the purified residuum from the crude petroleum at 
higher temperatures, " paraffin oils " are obtained together with a 
residue of pitch. These paraffin oils are filtered, while hot, through 
freshly burned bone-black, for the purpose of removing odor and 
color, and then subjected to distillation until the desired consistence 
or melting-point of the residuary portion is obtained. The three 
official varieties of petrolatum differ from each other simply in the 
graded removal of lower hydrocarbons. 

Petrolatum is not saponifiable and not subject to rancidity. It 
properly purified, it consists only of hydrocarbons, which are not af- 
fected at all by cold acids and alkalies and only slightly by hot 
acids ; hence the name paraffins has been given to the products, from 
the words parum, too little, and affinis, allied, on account of their 
lack of affinity for other substances. 

Hard paraffin is obtained partly as a residue from the above- 
mentioned paraffin oils and also largely by the purification with sul- 
phuric acid, etc., of ozokerite or mineral (earth) wax. It occurs as a 
white, crystalline, odorless, wax-like body, having a melting-point 
varying from 65° to 80° C. (149°-174° F.), according to its source. 
Ceresin is a yellow variety of purified earth wax, often used to 
adulterate yellow beeswax. 



CHAPTEE LVII. 

VOLATILE OILS AND RESINS. 

Volatile oils form a very important class of pharmaceutical 
plaut products. Their physical properties aud the mode of obtaining 
them have already beeu fully considered on pages 196-204. Chem- 
ically, volatile oils differ radically from fats and fixed oils, as they 
are not capable of saponification aud contain no glycerin. Moreover, 
by exposure to air, they undergo resinification, but do not become 
rancid. They may be said to consist of hydrocarbons of the aro- 
matic series, usually associated with oxygen derivatives, alcohols, 
aldehydes, compound ethers, acids, ketones, and phenols. While 
some volatile oils are complex mixtures, others are of very simple 
composition. The hydrocarbons found in volatile oils all belong to 
one of the following groups : terpenes of the composition C 10 H 16 , 
which include pinene, camphene, dextrorotatory limonene (known 
also as hesperidine, citreue, or carvene), Isevorotatory limonene, dip- 
entene or cinene, sylvestrene, and phellandrene; sesquiterpenes of 
the composition C 18 H 2i ; diterpenes of the composition C 20 H 32 ; 
polyterpenes of the composition (C 10 H 16 ).x 

Chemists must rely largely upon fractional distillation for separa- 
tion of the different constituents, in addition to which the examina- 
tion of volatile oils is materially aided by determination of their 
optical rotation by means of the polariscope, as explained on pages 
512-514 of the Pharmacopoeia. 

The behavior of volatile oils with acids, alkalies, and other re- 
agents must naturally vary greatly, owing to the diversity in their 
constitution. Those oils composed almost wholly of terpenes form 
either solid or liquid compounds with hydrochloric acid. Other oils 
are oxidized and converted into resin-like bodies by nitric acid, while 
sulphuric acid thickens some volatile oils aud completely chars others. 
Color reactions also occur between some of the oils and sulphuric 
and other acids. Alkali carbonates are without much effect on vol- 
atile oils unless the latter contain acids, but alkali hydroxides, in 
both aqueous and alcoholic solution, are more active, removing 
phenols, saponifying compound ethers, etc. Acid alkali sulphites, 
when added to volatile oils containing aldehydes, combine with the 
latter to form crystalline compounds. Iodine reacts violently with 
some oils, and bromine forms crystallizable tetrabromides with 
others. 

The study of the chemistry of volatile oils is a very comprehen- 
sive subject, and, while a full treatment thereof cannot be attempted 



598 PHARMACEUTICAL CHEMISTRY. 

in this book, the pharmacist of to-day should at least be made 
familiar with the constituents of the official volatile oils, as shown 
by investigations made during the past decade, whereby our knowl- 
edge of the subject has been so greatly enriched. The Descriptive 
Catalogue of Essential Oils, compiled by Dr. F. B. Power, 1894, 
gives probably the most complete information to be had in the Eng- 
lish language, at the present time, regarding recent determinations ot 
the composition of volatile oils. (The author is indebted to this 
publication for many valuable data, abstracted by permission of the 
compiler.) 

The Official Volatile Oils. 

Oil of Anise. The chief constituent of this oil, 90 per cent, and 
over, is anethol, C 6 H 4 OCH 3 C 3 H 5 , which solidifies at low temper- 
atures and is accompanied by an undetermined liquid portion, prob- 
ably a terpen e. 

Oil of Bergamot. The constituents of this oil are the terpenes, 
limonene, and dipentene, an alcohol, linalool, C 10 H 17 OH, and an 
ester, linaloyl acetate, also known as bergamiol, C 10 H 17 C 2 H 3 O 2 . This 
ester is usually present to the extent of 36-39 per cent., and upon it 
depends the value of the oil ; it is determined quantitatively by 
saponification with sodium hydroxide, as in the case of other com- 
pound ethers. 

Oil of Betula, also known as oil of sweet birch, constitutes prob- 
ably the bulk of the commercial oil of wintergreen. Very recent 
investigations (September, 1895), made by Power and Kleber, have 
shown that oil of sweet birch, in its uu rectified state, contains about 
99.8 per cent, of methyl salicylate, together with a very small amount 
of a paraffin, triacontan, C 30 H 62 , an aldehyde or ketone, and the ester, 
u H 24 O 27 ; it does not, however, contain the alcohol C 8 H 16 0, found 
in oil of gaultheria. The oil is always optically inactive, and, when 
rectified, would approximate so closely to pure methyl salicylate in 
composition as to be practically identical with it. The specific gravity 
of oil of sweet birch is identical with that of the natural oil of winter- 
green and like the latter the oil forms a clear solution with five times 
its volume of 70 per cent, alcohol at a temperature of 20°-25° C. 
(68°-77° F.). 

Empyreumatic oil of birch, known commercially as oleum rusci 
and also as oleum betulinum or oleum muscovitieum, is obtained by dis- 
tillation of birch tar or daggett, derived by destructive distillation 
from the wood of the common European birch, betula alba. The 
oil is of dark brown-red color, having a peculiar penetrating odor 
like that of Kussia leather, and somewhat resembles oil of cade in its 
medicinal properties. 

Oil of Bitter Almond. This oil consists of benzoic aldehyde, 
C 6 H 5 COH, with variable proportions of hydrocyanic acid. It does 
not pre-exist in the seed, but is produced from amygdalin (see 



VOLATILE OILS AND RESINS. 599 

^lucosides) by fermentation set up in the presence of water, thus, 
C 20 H 27 NO 11 +2H 2 O = C 6 H 5 COH + HCN + 2C 6 H 12 6 . Exposed to 
the air, the oil is oxidized to benzoic acid, C 7 H 6 2 , which occurs more 
rapidly in the absence of hydrocyanic acid. The official test for 
other volatile oils and nitrobenzene depends upon the removal of the 
benzoic aldehyde by means of acid sodium sulphite, forming the 
compound C 7 H 5 COH.NaHS0 3 . which enters into solution by the 
aid of heat. Synthetic oil of bitter almond, made from toluene and 
purified with acid sodium sulphite, is now extensively sold. 

Oil of Cade, obtained by destructive distillation of the wood of the 
prickly cedar, a species of juniper indigenous to the southern part of 
France, is also known as empyreumatic oil of juniper, and consists of 
a sesquiterpene, cadinene, C 15 H 24 , and a mixture of undetermined 
phenols. 

Oil of Cajuput. The chief constituents are a neutral body, cineol 
or eucalyptol, C 10 H 18 O (about 67 per cent.), an alcohol, terpineol, 
C 10 H 17 OH, and undetermined terpenes. The commercial article 
owes its green color to copper, as may be shown by the official test ; 
when redistilled the oil is colorless. 

Oil of Caraway is composed of a terpene, limonene, C 10 H 16 , and 
a ketone, car vol, C I0 H 14 O ; both compounds are dextrorotatory and 
are present in proportions varying from 35 to 50 of the former to 
65 to 50 of the latter. 

Oil of Chenopodium, also known as oil of wormseed, is said to 
contain a terpene, C 10 H 16 , and an oxidized body, C 10 H 16 O. 

Oil of Cinnamon. Ordinary oil of Chinese cinnamon, usually 
designated as oil of cassia, is the kind recognized in the Pharmaco- 
poeia. It consists chiefly of cinnamic aldehyde, C 8 H 7 COH, with 
some cinnamyl acetate, C 9 H 9 .C 2 H 3 2 , and small amounts of cinnamic 
acid, C 8 H 8 2 . The value of this oil, which is subject to adultera- 
tion, may be determined by means of a concentrated solution of 
acid sodium sulphite, the cinnamic aldehyde uniting with the alkali 
salt, leaving the other constituents intact ; the oil should lose at 
least three-fourths of its volume by this treatment, showing the 
presence of 75 per cent, of the aldehyde. A characteristic reaction 
of oil of cinnamon is the formation of a crystalline compound with 
nitric acid when equal volumes of the oil and acid are mixed at 0° 
C. (32° F.) ; the product is an addition-compound of cinnamic 
aldehyde and nitric acid, C 8 H 7 COHH]>r0 3 . Oil of Ceylon cinnamon, 
which has a finer aroma than the official oil, contains, besides cin- 
namic aldehyde, some eugenol and phellandrene. 

Oil of Cloves. The chief constituent of this oil is eugenol, C 6 H 3 . 
C 3 H 5 .OCH 3 .OH, a monatomic phenol, which is present in prime oil 
to the extent of from 80 to 90 per cent, and over ; besides this, the 
oil also contains a sesquiterpene, C 15 H 24 , called caryophyllene. The 
reaction with potassium hydroxide or ammonia, mentioned in the 
Pharmacopoeia, depends upon the formation of potassium or ammo- 
nium eugenol, C 10 H n O.OK or C 10 H lt O.ONH 4 . The value of oil of 



600 PHARMACEUTICAL CHEMISTRY. 

cloves lies wholly in the eugenol present, hence the quantitative 
determination of this body is the best method for valuation of the 
oil. By converting the eugenol into crystalline benzoyl eugenol, 
C^H^CgHgCC^, by means of benzoyl chloride, C 6 H 5 C0C1, as sug- 
gested by Thorns (see Amer. Journal Pharm., 1892, p. 508), the per- 
centage of eugenol in any sample of oil may be calculated from the 
weight of the new compound obtained. 

Oil of Copaiba consists chiefly of a sesquiterpene, C 15 H 24 , identical 
with that found in cloves and known as caryophylleue. It is readily 
oxidized by exposure to air. 

Oil of Coriander is composed of a terpene, pinene, C 10 H 16 , and an 
alcohol, linalool, C 10 H 17 OH. 

Oil of Cubeb. The composition of this oil varies somewhat with 
age. Recent oil, distilled from fresh fruit, consists chiefly of a ses- 
quiterpene, cadinene, C 15 H 24 , with some dipentene, C 10 H 16 , but, if old 
or obtained from old fruit, cubeb camphor, C 15 H 24 .H 2 0, is also present. 

Oil of Erigeron, better known as oil of fleabane, consists chiefly 
of dextrorotatory limonene, C 10 H 16 , together with an undetermined 
substance readily decomposed by heat. 

Oil of Eucalyptus. The composition of this oil depends largely 
on its source. The oils of Eucalyptus globulus and E. oleosa, 
which are specially mentioned in the Pharmacopoeia, consist chiefly 
of cineol or eucalyptol, C 10 H 18 O, a neutral body, to which they owe 
their medicinal and antiseptic virtues ; the first named oil contains 
also pinene and small amounts of various aldehydes, while the last 
named contains an aldehyde known as cuminol, C 9 H n .COH. The 
official test for the presence of considerable quantities of phellan- 
drene, depending upon the formation of crystalline phellandrene 
nitrite, C 10 H 16 N 2 O 3 , can be made more delicate, according to Power, 
by mixing the oil first with 5 Cc. of petroleum benzin, then 
adding the sodium nitrite solution, and lastly the glacial acetic acid, 
drop by drop, with vigorous agitation after each addition. Some 
eucalyptus oils contain also citral C 10 H 16 O, citronellal, C 10 H 18 O, and 
geraniol, C 10 H 17 OH. 

Oil of Fennel. This oil contains the terpenes, pinene, phellan- 
drene, and dipentene, together with fenchone, C I0 H 16 O, and anethol, 
C 10 H 12 O ; the latter is usually present to the extent of more than 50 
per cent, and separates in crystals upon a reduction of the temper- 
ature, hence the higher the temperature at which this occurs, the 
better the oil. 

Oil of Gaultheria. The true oil contains, according to Power and 
Kleber (September, 1895), about 99 per cent, of methyl salicylate, 
together with a small amount of a paraffin, probably triacontan, 
C 30 H 62 , an aldehyde or ketone, an apparently secondary alcohol, 
C 8 H 16 0, and an ester C 14 H 24 2 , thus resembling oil of sweet birch 
very closely in composition. It has a specific gravity of from 1.180 
to 1.187 at 15° C. (59° F.), and yields a clear solution when mixed 
with five times its volume of 70 per cent, alcohol at a temperature of 



VOLATILE OILS AXD RESIXS. 601 

from 20° to 25° C. (68°-77° F.). Neither oil of gaultheria nor oil 
of sweet birch contains any trace of benzoic acid or its esters, nor 
does either oil contain any terpene or sesquiterpene, as was at one 
time supposed. 

Pure fresh oil of wintergreen (gaultheria) always deviates a ray 
of polarized light to the left, aud this deflection should not be less 
than — 0° 25' in a 100 Mm. tube. 

Oil of Hedeoma. According to Kremers, this oil contaius pule- 
gone, C 10 H 16 O, and two ketones of the composition C 10 H 18 O, which 
are looked upon as reduction-products of the former body. Formic 
and acetic acids are also present. Commercially this oil is known as 
oil of pennyroyal. 

Oil of Juniper consists chiefly of pinene with some cadinene, 
C 15 H 24 , and a body, as yet undetermined, to which the peculiar odor 
and taste of the oil are due. The oil obtained from the fruit only 
should be used in pharmacy. 

Oil of Lavender Flowers. This oil contains two alcohols, linalool, 
C 10 H 17 OH, and geraniol, C 10 H 17 OH, a compound ether, linaloyl ace- 
tate, C 10 H 17 C 2 H 3 O 2 , and some cineol. The value of the oil resides in 
the compound ether, which is present to the extent of 30 or 36 per 
cent., and may be determined by saponification with sodium hy- 
droxide. 

Oil of Lemon contains dextrorotatory limonene, some pinene, and 7 
to 8 per cent, of an aldehyde, citral, C 10 H 16 O, to which the character- 
istic odor of the oil is due ; a small amount of citronellal, C 10 H 13 O r 
is also present. 

Oil of Mustard, Volatile. Like oil of bitter almond, this oil does 
not pre-exist in the plant ; it is obtained by macerating crushed black 
mustard seed, after the removal of fixed oil by expression, with 
water, when a reaction sets in between sinigrin, a glucoside, and my- 
rosin, an albuminoid body. Sinigrin is, chemically, potassium my- 
ronate, C 10 H 18 XS 2 KO 10 , which, under the influence of the albumin- 
oid ferment, is split up into allyl isosulphocyauate, acid potassium 
sulphate, and glucose, thus : C 10 H 18 XS 2 KO 10 ==C 3 H 5 CSX (volatile oil of 
mustard) +KHS0 4 -j-C 6 H 12 6 . Since the albuminoid my rosin is 
rendered inert at a temperature between 60° and 70° C. (140° and 
158° F.), mustard which has been heated to this point will not yield 
the volatile oil, nor can hot water be employed in its manufacture ; 
for the same reason, mustard plasters should never be dipped into 
water that is more than lukewarm. 

Volatile oil of mustard always contains traces of carbon disul- 
phide. It has been prepared synthetically by decomposing allyl 
iodide, C 3 H 5 I, by means of potassium sulphocyanate in alcoholic 
solution. 

White mustard seed does not yield volatile oil of mustard, since it 
does not contain sinigrin, but instead sinalbin, having the composition, 
C 30 H 44 X 2 S 2 O 16 . "When sinalbin reacts with myrosin in the presence 
of water, a very active, oily but non-volatile principle, to which the 



602 PHARMACEUTICAL CHEMISTRY. 

name acrinyl sulphocyanate, C 7 H 7 O.CSN, has been given, is formed, 
together with acid sinapine sulphate, (C 16 H 23 N0 5 )EI 2 S0 4 , and glucose, 

C6H 12 6 . 

The official method of valuation depends upon the formation of a 
crystalline compound, thiosinamine, by the action of ammonia on 
the oil of mustard, thus : C 3 H^SN+]m 3 =C 3 H 5 .CSN 2 H 3 . Since 
98.87 parts of the oil yield 115.88 parts of thiosinamine, 3 Gm. 
cannot yield more than 3.51 Gm. 

Oil of Myrcia. A complete analysis of this oil, also known as oil of 
bay, recently made by Power (March, 1895), has shown it to be of 
rather complex composition, containing two terpenes, myrcene, 
C 10 H 16 , and phellandrene, C 10 H 16 , two phenols, eugenol, C 6 H 3 . 
C 3 H 5 .OCH 3 .OH, and chavicol, C 6 H 4 C 3 H 5 OH, methyl-eugenol, 
C 6 H 4 C 3 H 5 (OCH 3 ) 2 , methyl-chavicol, C 6 H 4 C 3 H 5 OCH 3 , and one alde- 
hyde, citral, C 10 H 16 O. The chief constituents are eugenol and myr- 
cene ; the latter is very unstable and readily changed into the poly- 
meric diterpene C 20 H 32 , which explains the incomplete solution of 
the oil in alcohol, except in the case of freshly distilled oil. 

Oil of Nutmeg consists chiefly of pinene with probably some dipen- 
tine ; it contains also myristicol, C 10 H 16 O, and myristicin, C 12 H 14 3 . 

Oil of Orange Flowers, also known as oil of neroli, is said to con- 
sist of 40 per cent, of nerolyl acetate, C in H 17 C 2 H 3 0, 30 per cent, of 
a Isevorotatory alcohol, nerolol, C 10 H 17 OH, 20 per cent, of limonene 
and some geraniol. 

Oil of Orange Peel. Both the oil derived from the peel of bitter 
orange and that derived from the sweet orauge are officially recog- 
nized and show the same specific gravity and optical rotation. They 
consist chiefly of limonene with small proportions of citral and a 
lower boiling aldehyde. 

Oil of Peppermint. There is probably no volatile oil used in 
pharmacy of which a greater variety is offered for sale ; besides five 
or six different brands of American oil, oils distilled from English, 
German, and Japanese peppermint herb are also on the market. 
Oil of peppermint shows a greater complexity in composition than 
any other volatile oil known, a recent analysis (1894) by Power and 
Kleber of average American oil having developed the following con- 
stituents, fifteen in number: Acetaldehyde, C 2 H 4 0; acetic acid, 
HC 2 H 3 2 ; iso-valeraldehyde, C 5 H 10 O; iso-valerianic acid, HC 5 H 10 O 2 ; 
three isomeric terpenes, pinene, phellandrene, and limonene, C 10 H 16 ; 
<3ineol or eucalyptol, C 10 H I8 O ; menthone — a ketone — C 10 H 18 O ; 
menthol, C 10 H 19 OH; two compound ethers, menthyl acetate, 
C 10 H 19 C 2 H 3 O 2 , and menthyl iso-valeriante, C 10 H 19 C 5 H 10 O 2 ; a sesqui- 
terpene, cadinene, C 15 H 24 ; and a lactone of the composition C 10 H 16 O 2 . 

The most important constituent is menthol, of which good oil 
should contain at least 50 per cent., partly in a free state and partly 
in the form of esters ; such oil will readily respond to the official 
test in a freezing mixture. Japanese oil of peppermint, although 
rich in menthol (sometimes containing 79 per cent.), is not used 
medicinally, on account of its peculiar bitter and disagreeable taste. 



VOLATILE OILS AND BESINS. 603 

Oil of peppermint differs from other oils in the variety of its color- 
reactions with acids, as mentioned in the Pharmacopoeia. 

Oil of Pimento, or Oil of Allspice closely resembles oil of cloves in 
its constitution, but has a lower specific gravity. It contains eugeuol, 
C 6 H 3 C3H 5 .OCH 3 OH, and a sesquiterpene, C 15 H 24 . 

Oil of Hose. This oil shows a marked difference in constitution 
from other volatile oils, in that the solid crystallizable portion con- 
sists solely of a mixture of odorless hydrocarbons, one of which has 
the composition C^H^. The liquid portion of the oil, upon which 
its fragrance depends, is a mixture of geraniol, C 10 H 17 OH, with a 
small quantity of one or more undetermined substances of honey- 
like odor; it has been called rhodinol. The test given in the Phar- 
macopoeia for the presence in oil of rose of Turkish oil of geranium 
and oil of rose geranium, can be made more effective by using 5 Cc. 
of alcohol instead of 2 Cc, as officially directed. 

Oil of Rosemary is composed of pinene, cineol, C l0 H 18 O, borneol, 
C 10 H 17 OH, and camphor, C 10 H 17 OH. The finest commercial variety 
is that distilled from the flowers and known as the "Eperle* " brand. 

Oil of Santal. The official or East Indian oil of sandalwood is 
said to contain a body called santalal, C 15 H. ?4 0, and an alcoholic 
substance, sautalol, C 15 H 26 0, boiling at 300° C. (572° F.) and 
310° C. (590° F.) respectively. Inferior oils, produced in Aus- 
tralia and the West Indies, are all dextrorotatory, while the official 
oil is laevorotatory. Oil of cedar wood and fatty oils are readily de- 
tected by imperfect solubility of the oil in ten volumes of 70 per 
cent, alcohol. 

Oil of Sassafras consists chiefly of safrol, C 10 H 10 O 2 , with a very 
small amount of eugenol and a dextrorotatory hydrocarbon, C 10 H 16 , 
called safrene, probably identical with pinene. Safrol, at ordinary 
temperatures, is a perfectly colorless liquid of 1.108 specific gravity 
at 15° C. (59° F.); it is also found in Japanese camphor oil, from 
which it is now largely obtained. Commercial artificial oil of sassa- 
fras is not a synthetic product, but probably made from camphor oil. 

Oil of Savin contains pinene and the sesquiterpene, cadinene, 

^15^24' 

Oil of Spearmint differs radically in its composition from oil of pep- 
permint, containing laevorotatory limonene and laevorotatory carvol, 
C 10 H u O, with possibly some laevorotatory pinene. 

Oil of Tar. This oil, formed during the dry distillation of wood, 
is obtained from pine tar by fractional distillation. It is a complex 
mixture of hydrocarbons, acetic and other acids, and undetermined 
empyreumatic products. 

Oil of Thyme. The most important constituent of this oil is 
thymol, C 10 H 13 OH, a monatomic phenol ; the hydrocarbon cymene, 
C 10 H U , is also present, as well as very small quantities of bornyl es- 
ters. In some oils, thymol is entirely replaced by its isomer, carva- 
crol, whilst in others, both phenols are found present in equal 
amounts. 



604 PHARMACEUTICAL CHEMISTRY. 

Oil of Turpentine. The official oil, derived from American turpen- 
tine, consists almost wholly of dextrorotatory pinene, which, in the 
crude oil, is associated with resin and other oxidation-products de- 
pending upon age and exposure. These impurities, being removable 
by treatment with lime water and subsequent distillation, are there- 
fore not present in the official rectified oil, which alone should be em- 
ployed for internal use. 

Oil of Wintergreen, Synthetic or Artificial. This compound is 
recognized in the Pharmacopoeia as Methyl Salicylate, which name 
at once indicates its true chemical character, a compound ether. It 
may be prepared by distilling a mixture of salicylic acid, methyl 
alcohol, and sulphuric acid, when the following reaction occurs, 
HC 7 H 5 3 + CH3OH + H 2 S0 4 == CH 3 C 7 H 5 3 -f H 2 + H 2 S0 4 , 
methyl salicylate being volatized and condensed in suitable receivers, 
while diluted sulphuric acid remains in the still. For the purpose of 
purification, the product is thoroughly washed with water, decanted, 
and redistilled. 

The quality of this oil, as well as that of the oils of betula and 
gaultheria, is ascertained by means of decomposition with sodium 
hydroxide, as directed in the Pharmacopoeia. Sodium salicylate and 
methyl alcohol are formed according to the following equation, 
CH 3 C 7 H 5 3 + NaOH = NaC 7 H 5 3 + CH 3 OH, the former dissolv- 
ing upon application of heat and subsequently yielding a precipitate 
of salicylic acid upon supersaturation with hydrochloric acid. 

Derivatives of Volatile Oils. The Pharmacopoeia recog- 
nizes several compounds which, being obtained directly from volatile 
oils, should be considered at this point. 

Camphor. This term is applied to compounds having the com- 
position C 10 H 16 O, which occur in a number of essential oils and are 
solid at ordinary temperature. They are no doubt the result of oxi- 
dation of hydrocarbons in the plant, and stand in the relation of a 
ketone to the alcohol borneol, C 10 H ]7 OH. Official camphor is de- 
rived solely from the wood of the camphor tree of China and Japan. 
When camphor wood is heated in the stills the camphor volatilizes 
and sublimes in the form of small grains which come to this country 
as crude camphor. It is accompanied, as a by-product, by oil of 
camphor, a liquid of complex composition, containing not less than 
four hydrocarbons, pinene, phellandrene, dipentene, and cadinene, 
besides five oxidized bodies, cineol, camphor, terpineol, safrol, and 
eugenol. 

The term artificial camphor has been given by some to terpin 
hydrate, but it is generally applied to terpene hydrochloride, 
C 10 H 16 HC1, obtained by saturating oil of turpentine, dissolved in 
twice its volume of carbon disulphide, with dry hydrochloric acid 
gas. The compound forms a white, plastic, crystalline mass, melting 
at 125° C. (257° F.) and possessing the odor and appearance of 
ordinary camphor. If terpene hydrochloride be heated with potas- 



VOLATILE OILS AND RESINS. 605 

sium stearate in a sealed tube, solid terecamphene, C 10 H 16 , is formed, 
which, when boiled with potassium diehromate and dilute sulphuric 
acid, takes up oxygen and is converted into camphor, C 10 H 16 O. 

Menthol, C 10 H 19 OH. This body, forming the chief constituent of 
oil of peppermint, is obtained now almost altogether from the Japanese 
oil, by simple refrigeration, and is then purified by recrystallization. 
Its chemical character is that of a secondary alcohol, yielding by 
moderate oxidation with potassium diehromate and sulphuric acid a 
ketone, menthone, C 10 H 18 O, and combining with organic acids to form 
compound ethers, such as menthyl acetate, benzoate, butyrate, 
formate, etc. By means of dehydrating agents, menthol is converted 
into the hydrocarbons menthene and dimentheue. 

Monobromated Camphor. This compound is obtained by heating 
camphor and bromine together in a flask or retort (preferably with 
the addition of water or chloroform) until reaction ceases, then 
allowing the yellowish solution to crystallize, heating until the mass 
becomes white, and recrystallizing from alcohol or benzin. The re- 
action involves the formation of camphor dibromide, C 10 H 16 OBr 2 , 
which splits up into camphor monobromide and hydrobromic acid, 
C 10 H 16 OBr 2 = C 10 H 15 BrO + HBr, the latter distilling over with the 
water or chloroform. 

Terebene. This preparation is obtained by the action of concen- 
trated sulphuric acid on oil of turpentine, the acid being gradually 
added to the oil ; the mixture is allowed to stand for a day, after 
which the supernatant layer is removed, neutralized with chalk, and 
distilled. Careful investigations by Power and Kleber (1894) have 
shown that the statements in the Pharmacopoeia regarding terebene 
are erroneous, and that, in its chemical properties, it does not resem- 
ble oil of turpentine. While the latter oil, as before stated, consists 
almost wholly of dextrorotatory pinene, true terebene consists chiefly 
of the hydrocarbons dipentene and terpinene, with some cymol aud 
camphene, and is optically perfectly inactive ; the latter is an im- 
portant test for the presence of unaltered oil of turpentine. The 
specific gravity of terebene is about 0.855 instead of 0.862 at 15° C. 
(59° F.) and its boiling point between 170° and 185° C. (338° and 
365° F.) instead of 156°-160° C. (312.8°-320° F.). 
- Terpin Hydrate, C 10 H 18 (OH) 2 -f- H 2 C This compound may be 
obtained by allowing a mixture of four parts of rectified oil of tur- 
pentine, 3 parts of 80 per cent, alcohol, and 1 part of nitric acid to 
stand in large, shallow dishes for several days ; the crystals which 
have separated may then be drained, dried between filter paper, and 
recrystallized from 95 per cent, alcohol rendered slightly alkaline to 
remove adhering acid. The yield is about 12 per cent, of the weight 
of the oil of turpentine used, and the operation should always be per- 
formed in the cold, as, during hot weather, resinification of the oil 
will occur in place of the formation of crystals. Terpin hydrate, 
when fused or rendered anhydrous over sulphuric acid, yields terpin, 
C 10 H 13 (OH) 2 , a diatomic alcohol, which, when distilled with moder- 



606 PHARMACEUTICAL CHEMISTRY. 

ately dilute sulphuric acid, loses water and is changed chiefly into 
terpineol, C 10 H 17 OH, a substance largely employed in perfumery on 
account of its very fragrant odor, resembling that of fresh lilacs. 

Thymol, C 10 H 14 O or C 6 H 3 .CH 3 .C 3 H 7 OH. This body, chemically 
known as methyl-propyl phenol, occurs in several volatile oils, and is 
obtained bv treating the residue left upon distilling the oils below 
200° C. (392° F.) with solution of soda, whereby thymol is dissolved 
as sodium-thymol, C 10 H 13 ONa. When the solution has become clear 
by subsidence, thymol is liberated by means of hydrochloric acid and 
purified by distillation and crystallization ; if necessary, it is also de- 
colorized by treatment with animal charcoal. 

Resins. 

Comparatively little is known as yet regarding the chemical com- 
position of resins which occur in plauts either alone or in combina- 
tion with volatile oils as oleoresins or with gums as gum resins. In- 
vestigations are now in progress in the hands' of Prof. Tschirch of 
Berne, Switzerland, and his colaborers, and no doubt, in the course of 
a few years, much light will be shed upon this now rather obscure 
subject. This much has already been established, that resins are 
largely composed of organic acid esters or compound ethers of certain 
alcohols, to which latter the general name resinol has been applied ; 
some of these alcohols give reactions similar to those characteristic of 
the tannins and have therefore been designated as resinotannols. 
Thus we have benzoresinol, storesinol, peruresinotannol, toluresino- 
tannol, etc. Some resins have decidedly acid properties, while others 
are known to be anhydrides, as in the case of common pine resin or 
colophony, which is chiefly composed of abietic anhydride, C^H^C^; 
one of the resins found in copaiba is a crystalline acid, called copaivic 
acid, having the elementary composition, C 20 H 30 O 2 ; the resin obtained 
from guaiacum wood and officially recognized as guaiac, consists 
largely (70 per cent, and over) of guaiaconic acid, C 19 H 20 O 5 , to which 
the well-known color reactions of guaiac with oxidizing agents are due. 

Resin of Scammony consists almost wholly of scammonin, 
C 34 H 56 16 , the anhydride of scammonic acid, which behaves like a 
glucoside. Jalap resin consists of two distinct resins which can be 
separated from each other by ether, the one insoluble in that men- 
struum, and constituting about 70 per cent, of the official resin, con- 
sists almost entirely of con volvulin, C 31 H 50 O 16 , an anhydride possess- 
ing glucosidal properties and being colorless when pure. The official 
resin of podophyllum is a complex mixture, containing an acid called 
podophyllinic acid, insoluble in ether, and a substance to which the 
name podophyllotoxin has been given ; the latter, which constitutes 
about 50 per cent, of the official product, is said to be the active 
purgative principle. Both these substances are soluble in chloroform, 
and may be separated by addition of ether to the chloroformic solu- 
tion, which precipitates podophyllinic acid ; upon evaporation of the 
ethereal solution podophyllotoxin is obtained. 



CHAPTEE LVIII. 

ORGANIC ACIDS. 

Of the large number of compounds termed organic acids, only the 
few that are of special interest in pharmacy have been officially recog- 
nized. Organic acids are considered as derived from hydrocarbons 
or their alcohols, by replacement of hydrogen or hydroxyl by the 
univalent group carboxyl, C0 2 H, and vary in their basicity as one, 
two, or three carboxyl groups may have been taken up, carrying with 
them one, two, or three atoms of replaceable hydrogen, as in the case 
of inorganic acids. The official organic acids are acetic acid, benzoic 
acid, citric acid, gallic acid, lactic acid, oleic acid, salicylic acid, stearic 
acid, tannic acid, and tartaric acid. Diluted hydrocyanic acid, al- 
though usually reckoned among the inorganic acids, is preferably 
considered at this point, since cyanogen is a carbon compound prob- 
ably derived from hydrocarbons by substitution of nitrogen for 
hydrogen. Oxalic and valerianic acids, although not officially recog- 
nized, are both of interest to pharmacists, as is also meconic acid. 

Acetic Acid, HC 2 H 3 2 or CH 3 C0 2 H. This acid has already 
been considered in connection with the derivatives of cellulose on 
page 549. 

Benzoic Acid, HC 7 H 5 2 or C 6 H 5 C0 2 H. Several methods are 
in use for obtaining this acid from benzoin, the balsamic resin from 
which it takes its name. 

Both a dry and a wet process are employed for extracting the acid 
from the resin, in which it exists in a free state. The former is by 
sublimation, benzoin in coarse powder, which has been dried over 
lime, being heated in shallow iron pans covered with a porous dia- 
phragm and connected with a suitable condenser, carefully regulated 
sand-bath heat being used so as to avoid contamination of the acid with 
other products, partly the result of decomposition, which volatilize 
at a temperature approaching 200° C. (392° F.). The yield of acid 
by this method ranges from 6 to 8 per cent, of the weight of ben- 
zoin used, the fused resin retaining a considerable portion which can 
be recovered by the wet method ; sublimed acid is never chemically 
pure, being always accompanied by a volatile oil to which the pecu- 
liar odor of the acid is due. 

The wet method consists in treating powdered benzoin for some 
time with warm milk of lime, and finally boiling the mixture and 
filtering while hot. The filtrate is supersaturated with hydrochloric 



608 PHARMACEUTICAL CHEMISTRY. 

acid, the crude benzoic acid being allowed to crystallize and then 
purified by resolution in boiling water, with the addition of animal 
charcoal, filtered and again crystallized. In this process calcium 
benzoate, Ca(C 7 H 5 2 ) 2 , is first formed and then decomposed with 
hydrochloric acid, whereby benzoic acid is liberated while calcium 
chloride remains in solution, thus, Ca (C 7 H 5 2 ) 2 -f 2HC1 = 2HC 7 H 5 2 
-f CaCl 2 . Benzoic acid obtained by this method, is of fine white 
appearance, and devoid of the peculiar aroma of sublimed acid. 

Of late years synthetic benzoic acid has been extensively produced, 
and the Pharmacopoeia recognizes both the natural and synthetic 
products. The latter is made from toluene, C 6 H 5 CH 3 , by passing 
chlorine gas into it while boiling until an increase in weight is no 
longer observed. Toluene is thereby converted into benzyl trichloride, 
C 6 H 5 CC1 3 , which liquid, when treated with water under pressure, is 
converted into benzoic and hydrochloric acids, thus C 6 H 5 CC1 3 + 
2H 2 = C 6 H 5 C0 2 H -f- 3HC1 ; the benzoic acid is separated by 
straining and washed with cold water until free from hydrochloric 
acid. It is important in this process that the chlorine gas be passed 
into the boiling toluene in diffused daylight, to avoid the formation 
of other products. 

Large quantities of benzoic acid are also made from the urine of 
cattle and horses, which contains hippuric acid, or benzoyl glycocoll. 
By boiling hippuric acid with strong hydrochloric acid, the former 
absorbs water and is split up into benzoic acid and glycocoll, thus : 
C 6 H 5 COC 2 H 3 NH0 2 + H 2 = C 6 H 5 C0 2 Ii + C 2 H 3 NH 2 2 . Ben- 
zoic acid from this source is always accompanied by a fetid odor, 
which is removed by recrystallization and sublimation with benzoin. 

Citric Acid, H 3 C 6 H 5 7 + H 2 or C 3 H 4 OH(C0 2 H) 3 + H 2 0. 
This acid belongs to the class known as fruit acids, and, although 
occurring in many plants, is obtained for use solely from lemons and 
limes. It is manufactured both in this country and Europe, on a 
large scale, from the juice of immature fruit, which contains from 
6-8 per cent, of acid. The juice is first clarified by ebullition and 
then neutralized by addition of chalk, the resulting calcium citrate 
being washed with boiling water, in which it is sparingly soluble, 
and finally decomposed by means of diluted sulphuric acid ; the 
newly formed calcium sulphate is removed by straining, the solution 
of citric acid being concentrated and allowed to crystallize in large 
wooden vats lined with lead. If necessary, the crystals of citric 
acid are redissolved in water, the solution being subsequently filtered 
through animal charcoal, to remove color, and recrystallized. 

As citric acid crystallizes better from solutions containing a little 
sulphuric acid traces of the latter are generally found in the com- 
mercial article. Small particles of metal found adhering to the 
crystals and deposited in solutions thereof are lead, derived from the 
crystallizing vats. Contamination with crystals of tartaric acid can 
be readily detected by placing some of the crystals in a small dish 



OR GANIC A CIDS. 609 

with a little solution of potassa ; the crystals of citric acid slowly 
dissolve, while those of tartaric acid gradually become opaque, 
owing to the formation of acid potassium tartrate. The Pharmaco- 
poeia requires absolute purity for citric acid, with the exception of 
very small traces of sulphuric acid. The official test for the pres- 
ence of tartaric and oxalic acids depends upon the solubility of 
potassium citrate in acetic acid, in which the tartrate and oxalate are 
insoluble. 

Solutions of citric acid gradually separate fungous growths; this 
can, however, be prevented by addition of 5 or 10 per cent, of alcohol. 

Diluted Hydrocyanic Acid. The official preparation of this 
name is an aqueous solution of gaseous hydrocyanic acid, HCN, 
prepared by decomposiug a solution of potassium ferrocyanide with 
sulphuric acid, in a flask or retort, and conducting the resulting 
vapors into distilled water. In this process the following reactions 
occur: 1. The formation of hydroferrocyanic acid, thus, K 4 Fe(CN) 6 
+ 2H 2 S0 4 = H 4 Fe(CN) 6 + 2K 2 S0 4 ; 2. The decomposition of a 
further portion of potassium ferrocyanide by the newly formed acid 
in the presence of sulphuric acid, thus, K 4 Fe(CN) 6 -|- H 4 Fe(CN) 6 
+ H 2 S0 4 = 6HCX + K 2 S0 4 + K 2 Fe(Fe(CN) 6 ), hydrocyanic acid 
being evolved, while potassium sulphate and potassio-ferrous ferro- 
cyanide, or Everitt's salt, remain in the flask or retort ; the latter 
salt is white at first, but gradually changes to blue. Aqueous vapor 
of course passes over with the vapor of the acid, both of which are 
usually condensed in a Liebig condenser interposed between the 
retort aud receiver. The directions of the Pharmacopoeia are to con- 
tinue distillation until the original volume of the mixture has been 
reduced to about one-half, and then to dilute the contents of the 
receiver with sufficient distilled water that the finished product shall 
contain 2 per cent, by weight of absolute hydrocyanic acid. 

The quantity of water required for dilution of the distillate is 
readily ascertained by first determining volumetrically the amount 
of absolute HCN present; this is done by titrating a small weighed 
portion with decinormal silver nitrate solution, using potassium 
chromate as an indicator. Since silver chroraate is soluble in both 
acid and alkaline liquids, it becomes necessary to neutralize the acid 
liquid, and for this purpose magnesium hydroxide is preferable to 
soda or potassa, as a slight excess of it is not hurtful — in fact, serves 
to sharpen the end reaction by providing a white background, 
against which the red color is more plainly seen. The equation, 
HCN + AgN0 3 == AgCN -[- HNO s , shows that 2d.98 parts of ab- 
solute hydrocyanic acid require 169.55 parts of silver nitrate for 
complete decomposition ; hence each Cc. of t N q- AgX0 3 solution rep- 
resents 0.002698 Gm. of HCN", and, as red silver chromate is not 
permanently formed until all hydrocyanic acid has been removed, 
the number of cubic centimeters of decinormal silver solution re- 
quired to produce the permanent red color, multiplied by 0.002698, 

39 



610 PHARMACEUTICAL CHEMISTRY. 

gives the total quantity of hydrocyanic acid present in the sample 
used for the assay, which, multiplied by 100 and divided by the 
weight of the sample, expresses the percentage of absolute acid. 
Thus, if 0.27 Gm. of the distillate requires 3.4 Cc. of ^ AgNO s 
solution, 3.4 per cent, of absolute HON is present, for 3.4 X 
0.002698 = 0.0091732, which multiplied by 100 and divided by 0.27 
= 3.39 -f- or 3.4. The amount of water necessary for dilution of 
the distillate can now be found by simple calculation, according to 
the rule stated on page 65, namely : multiply the total weight of the 
distillate by the percentage of absolute acid found and divide the 
product by the percentage required (which in this case is 2 per 
per cent.) ; the quotient indicates the weight to which the distillate 
must be brought by the addition of distilled water. If, from the 
weight so found, the weight of the original distillate be subtracted, 
the remainder will indicate the weight of water to be added. 

As the vapor of hydrocyanic acid is very poisonous, special care 
must be observed that all joints of the flask, tubing, etc., be secure, 
so as to prevent leakage, and to guard against the bumping of the 
liquid in the flask, frequently observed, a tin hood may be placed 
over it or a spiral of glass or platinum be suspended in the liquid. 

The alternative formula in the Pharmacopoeia for making the 
official acid is simple, and offers a convenient method for rapidly pre- 
paring small quantities. Six Gm. of silver cyanide will yield 1.21 -f- 
Gm. of absolute hydrocyanic acid, w T hich, dissolved in 60 Cc. of fluid 
as directed in the formula, makes a 2 per cent, solution ; if strictly 
official hydrochloric acid be used, a very slight excess of the latter 
will be present. 

Solutions of hydrocyanic acid are unstable, hence the official diluted 
acid is a very unsatisfactory preparation, even if carefully kept in 
small, tightly closed amber vials. Good sound corks are probably 
preferable to glass stoppers, as they fit more closely, as a rule. 
Various substances, such as sulphuric and hydrochloric acids, diluted 
alcohol, etc., have been suggested for the preservation of the diluted 
acid, but thus far none have proven strictly reliable. 

A strong solution of hydrocyanic acid, known as Scheele's acid, 
contains 5 per cent, of absolute HCN, but is not used in this country 
for medicinal purposes. 

The test with potassa, ferrous sulphate, and ferric chloride, men- 
tioned in the Pharmacopoeia, is generally known as Scheele's test 
for hydrocyanic acid, and depends upon the formation of ferric fer- 
rocyanide, or Prussian blue, bv alkali cyanides. The reactions occur- 
ring are as follows: 1. HCN+KOH =KCN + H 2 ; 2. 18KCN 
+ 3FeS0 4 + 2Fe 2 Cl 6 = Fe f (Fe(CN) 6 ) 3 + 12KC1 + 3K 2 SO,. In 
the presence of an excess of alkali hydroxide, however, as in the 
official test, the blue salt undergoes decomposition, alkali ferrocy- 
anide entering into solution and ferroso-ferric hydroxide being pre- 
cipitated ; hence the addition of hydrochloric acid is made to redis- 
solve the latter when ferric ferrocyanide will be precipitated. 



OEGAXIC ACIDS. 611 

Gallic Acid, HC 7 H 5 5 + H 2 or C 6 H 2 (OH) 3 C0 2 H - H 2 0. 
When powdered nutgall is macerated for some time with water the 
astringent principle contained therein undergoes a change, becoming 
but sparingly soluble in cold water. Xutgalls contain tannin, 
which is now accepted to be an anhydride convertible into gallic 
acid by the absorption of water, thus : C u H 10 O 9 + H 2 = 2HC 7 H.0 5 . 
The usual plan of obtaining gallic acid is to form a thin paste of 
nutgall with water, which is exposed to the air in a warm place for 
a month, with occasional stirring and replacement of water that may 
evaporate ; at the end of that time the paste is expressed, the liquid 
being rejected, and the residue boiled with distilled water for a few 
minutes ; the mixture is filtered while hot through animal charcoal 
and allowed to crystallize. The crystals, if not sufficiently free from 
color, are again dissolved in hot water, filtered as before, recrystal- 
lized, and dried. 

The British Pharmacopoeia directs to boil coarsely-powdered nut- 
gall with diluted sulphuric acid for half an hour and strain the 
mixture while hot ; upon cooling, the liquid separates crystals of 
gallic acid. The object of the sulphuric acid is simply to hasten 
the combination of the tannin with water, and thus save time. 

Gallic acid is readily distinguished from tannic acid by its greatly 
decreased solubility in water, alcohol, and glycerin. Alkali citrates 
are said to increase the solubility of gallic acid in water to a marked 
degree. Its aqueous solution is, moreover, not precipitated by addi- 
tion of albumin, starch, or gelatin solution, and the bluish-white 
precipitate formed upon addition of lime-water is redissolved by an 
excess of gallic acid ; a large excess of lime-water causes the liquid to 
assume a pink tint. Gallic acid causes no precipitation in alkaloidal 
solutions. 

Medicinally gallic acid is unlike tannic acid in so far that, exter- 
nally applied, it exerts no astringent effect, although it readily con- 
trols passive hemorrhages when internally administered. 

Pyrogallol, also known as pyrogallic acid, is a derivative of 
gallic acid and recognized in the Pharmacopoeia. Chemically it is 
a triatomic phenol, having the composition C 6 H 3 (OH) 3 , and may be 
obtained by subliming previouslv dried gallic acid in an oil-bath at 
a temperature of 200 o< or 210° C.*(392° or 410° F.) ; the yield by this 
method amounts to about 30 per cent. If gallic acid be heated with 
two or three times its weight of water for half an hour at the above- 
named temperature, under pressure in a suitable boiler, in such a 
manner that the liberated carbon dioxide can escape, a somewhat 
colored solution of pyrogallol will result, which, boiled with animal 
charcoal, filtered, and evaporated, yields an almost colorless crystal- 
line mass, from which pure pyrogallol may be obtained ; as the yield 
amounts to nearly 75 per cent, of the weight of gallic acid used, this 
process is preferred by manufacturers. In either case the chemical 



612 PHARMACEUTICAL CHEMISTRY. 

change is the same, gallic acid being split np into pyrogallol and 
carbon dioxide, thus : HC 7 H 5 5 = C 6 H 3 (OH) 3 + C0 2 . 

Pyrogallol is readily darkened by exposure to air and light, 
owing to oxidation ; hence it must be carefully preserved in tightly 
closed amber vials. It is very soluble in water, alcohol, and ether, 
and contamination with gallic acid may thus be detected. 

As pyrogallol is poisonous, a derivative product has been intro- 
duced in its place, namely, gallacetophenone, or galladophenone, pre- 
pared by heating a mixture of pyrogallol, zinc chloride, and glacial 
acetic acid to 148° C. (298.4° F.) and adding water to the fusion 
while hot ; the resulting product may be recrystallized from boiling 
water. It occurs as a crystalline powder of dirty flesh-color, having 
the composition C 6 H 2 (C 2 H 3 0)(OH) 3 . 

Lactic Acid. The official acid is an aqueous solution of lactic 
acid, HC 3 H 5 3 or CH 3 CHOHC0 2 H, containing 75 per cent, by 
weight of the absolute acid. Three varieties of lactic acid are known, 
namely, isolactic or ethyledene lactic acid, sarcolactic acid, and ethy- 
lene lactic acid, of which the first alone is officially recognized ; it is 
obtained by fermentation of a mixture of either milk-sugar or in- 
verted sugar (see page 567), milk, or cheese and water, at a temper- 
ature between 25° and 35° C. (77° and 95° F.) ; chalk or zinc 
oxide is added to neutralize the acid as fast as formed, since butyric 
acid is otherwise apt to be produced if much free lactic acid is 
present. The resulting calcium, or zinc lactate, is subsequently re- 
crystallized and decomposed by means of sulphuric acid or hydrogen 
sulphide, the mixture filtered and the solution of lactic acid evapo- 
rated. Complete evaporation of the water is not practicable, since 
the lactic acid would undergo decomposition, the elements of water 
being split off and insoluble lactic anhydride formed ; hence the 
Pharmacopoeia recognizes a very strong solution in place of the 
absolute acid. The temperature is an important factor in the fer- 
mentation of milk, as below 25° C. (77° F.) acetic acid will be 
formed, above 35° C. (95° F.) butyric acid ; hence the largest yield 
of lactic acid is produced between these two degrees of heat. 

Besides the official lactic acid two other varieties occur ou the 
market, known as concentrated and dilute lactic acid respectively; 
but, since neither strength nor specific gravity is specified on the 
label, they should not be employed by pharmacists in prescriptions 
or otherwise. 

The reaction between lactic acid, potassium permanganate, and 
sulphuric acid, mentioned in the Pharmacopoeia, resulting in the 
development of an odor of aldehyde, has already been explained on 
page 477 under strontium lactate. 

Meconic Acid, H 3 C 7 H0 7 -j- 3H 2 0. This acid is of interest 
chiefly as a constituent of opium, and also on account of its peculiar 
reaction with ferric chloride, which can be used as a test for prepara- 



OR GANIC A CIDS. 613 

tions of opium ; ferric meeonate possesses a blood-red color, like that 
of ferric acetate and sulphocyanate, but may be distinguished from 
the former by its indifference to dilute hydrochloric acid, and from 
the latter by its indifference to mercuric chloride. Reducing agents, 
such as stannous chloride and alkali hypochlorites, discharge the 
color of ferric meeonate. Meconic acid may be obtaiued by precipi- 
tating a concentrated infusion of opium with calcium chloride, de- 
composing the resulting calcium meeonate with warm dilute hydro- 
chloric acid and recrystallizing from water. 

Oleic Acid, HCjgH^O,; or C^H^CCXjH. In the chapter on fats 
and fixed oils this acid has been mentioned as being found in nearly 
all liquid fats. It is usually obtained of variable quality in a crude 
state in the manufacture of candles, being then known as red oil ; 
for pharmaceutical purposes the crude acid can be sufficiently puri- 
fied by simply cooling the same to 5° C. (41° F.) and separating the 
liquid portion from palmitic and other acids. Such an acid is recog- 
nized in the Pharmacopoeia. A still purer acid may be obtained by 
saponifying expressed oil of almond with lead oxide, dissolving the 
lead oleate in petroleum benzin and decomposing the solution with 
dilute hydrochloric acid ; after removal of the benzin by evapora- 
tion, the oleic acid may be washed with water. When perfectly 
pure, oleic acid is colorless, odorless, and tasteless, but rapidly be- 
comes colored upon exposure to air and light. 

The test for appreciable quantities of palmitic and stearic acids, 
mentioned in the Pharmacopoeia, depends upon the formation of lead 
oleate, palmitate, and stearate, the former of which is soluble in 
ether, while the latter two are insoluble. 

Oxalic Acid, H 2 C 2 4 + 2H 2 or (C0 2 H) 2 + 2H 2 0. Although 
this acid occurs in numerous plants, chiefly in the form of acid 
potassium oxalate, it is obtained for the market wholly by synthetic 
methods. If sawdust be made into a pasty mass with strong solu- 
tion of potassa, or potassa and soda, the mass then heated and kept 
at a temperature of 205° C. (401° F.) for one or two hours and 
dried, a gray powder of crude alkali oxalates will be obtained ; by 
treatment with milk of lime, calcium oxalate results, which is then 
decomposed with sulphuric acid and the solution of oxalic acid is 
concentrated and crystallized. A much larger yield is said to be 
obtained by heating sodium hydroxide with carbonic oxide to 100° 
C. (212° F.), whereby sodium formate, NaHC0 2 , is produced, 
which is then further heated to 400° C. (752° F.), with exclusion of 
air as far as possible, and converted into sodium oxalate, from which 
the acid is liberated as above. 

Oxalic acid is used in medicine only in the form of ferrous and 
cerous oxalates, but is a valuable reagent in chemical analysis. 

Salicylic Acid, HC 7 H 5 3 or C 6 HpHC0 2 H. Since the intro- 
duction of salicylic acid into medicine, nearly all thus used has been 



614 PHARMACEUTICAL CHEMISTRY. 

prepared synthetically from carbolic acid or phenol ; small quantities 
are also obtained by treating oil of wiutergreen, methyl salicylate, 
with potassa and decomposing the resulting potassium salt with an 
acid. In the synthetic process, the first step is the manufacture of 
sodium carbolate, or sodium phenol, C 6 H 5 ONa, by saturating car- 
bolic acid with sodium hydroxide. This compound is then dried 
and treated with carbon dioxide, whereby sodium phenol carbonate 
is formed, thus, C 6 H 5 ONa -J- C0 2 = NaC 6 H 5 C0 3 ; this is heated in 
tightly-closed vessels, or in retorts through which a stream of carbon 
dioxide is passing, to 130° C. (266° F.), when it is converted into 
sodium salicylate, NaC 7 H 5 3 . This is the process now generally 
employed, and is a modification of Kolbe's original method, in 
which only one-half of the phenol was utilized, the remainder dis- 
tilling over at a higher temperature. The crude sodium salicylate 
is dissolved in water and decomposed by means of hydrochloric acid ; 
the resulting mixture is drained, washed with cold water, and finally 
dissolved in boiling water from which salicylic acid crystallizes on 
cooling and can be purified by solution in diluted alcohol, decolorized 
with auimal charcoal, and recrystallized. 

Salicylic acid furnishes several derivative products used in medi- 
cine, one of which is recognized in the Pharmacopoeia under the 
name Salol; this can also be looked upon as a derivation of phenol ; 
but, as it is more closely allied to salicylic acid in its therapeutic 
effects, it is generally classed with the same. 

Salol. This title is simply a copyrighted name applied to the 
phenyl ester of salicylic acid, more properly called phenyl salicylate. 
Several methods are known for preparing salol, such as treating a 
mixture of sodium phenol and sodium salicylate with phosphorus 
oxychloride, or passing a slow current of phosgene (carbonyl chloride) 
into a warm mixture of the two salts; in both cases new sodium salts 
are formed as by-products and the resulting salol is dissolved in 
alcohol and crystallized. A later and simpler process consists in 
heating salicylic acid, contained in a flask with a long narrow neck, 
in an oil-bath, to 220° or 230° C. (428° or 446° F.) ; air is ex- 
cluded by passing a stream of carbon dioxide into the flask, the long 
neck of which permits only vapors of. water and carbon dioxide to 
escape. The salicylic acid is first changed by heating into its anhy- 
dride, thus, 2HC 7 H 5 O s = (C 6 H 4 0O 2 H) 2 O + H 2 ; this is then split 
up into phenyl salicylate and carbon dioxide, thus : (C 6 H 4 C0 2 H) 2 
= C 6 H 5 C 7 H 5 O s 4- C0 2 . The resulting compound is dissolved in 
alcohol and crystallized, as in the other methods. 

Other derivatives of minor importance are : salipyrine, or anti- 
pyrine salicylate ; salophen, a compound of salicylic acid and acetyl- 
amidophenol, a group far less poisonous than phenol ; saliphen, a 
compound of salicylic acid and phenetidin ; salicylamide, a compound 
produced by the action of ammonia on methyl salicylate ; diiodosalol, 



ORGANIC ACIDS. 615 

a condensation product of phenol and diiodosalicylic acid ; cresalol, 
or cresol salicylate ; salumin, aluminum salicylate. 

Stearic Acid, HC 18 H 35 2 or C 17 H 35 C0 2 H. This acid, which is 
of very little use in pharmacy, except iu the preparation of glycerin 
suppositories, is largely obtained in the manufacture of glycerin from 
tallow, by treatment with water and superheated steam, as explained 
on page 195. The commercial article is rarely pure, often consist- 
ing wholly of stearin ; for pharmaceutical purposes, it should, at 
least, respond to the official requirement regarding the limit of un- 
decomposed fat. Solubility in alcohol also serves to distinguish 
stearic acid from stearin. 

Tannic Acid, HC 14 H 9 9 . The official tannic acid is that more 
specifically known as gallotannic acid, from its source, nut-gall, to 
distinguish it from related compounds found in the bark of various 
oaks, chestnut, etc.; it has, however, also been met in the leaves 
of tea and sumac. Absolutely pure gallotannic acid is no doubt 
digallic acid, or an anhydride of gallic acid, as stated on page 611, 
and, as such, its composition would be represented by the formula 
(C 6 H 2 (OH) 2 C0 2 H) 2 ; the commercial article is, however, as a rule, 
contaminated with variable proportions of glucose in weak combina- 
tion, which formerly gave support to the view that tannic acid was 
a glucoside. The true chemical character of tannin was first 
announced by Schiff, in 1871, and corroborated by Etti, in 1884. 
The subject of the various tannins has been carefully studied in this 
country, during the past five or six years, by Prof. H. R. Trimble, 
who has laid down the results of his labors in a valuable and ex- 
tended monograph, entitled Ihe Tannins, which work has been 
freely consulted by the writer. 

Different methods are employed by manufacturers for the extrac- 
tion of gallotannic acid, giving rise to the varieties known as ether-, 
alcohol-, and water-tannin. Chinese or Japanese galls are preferred 
to the Turkish variety, on account of their richness in tannic acid, 
from 60 to 65 per cent., and greater freedom from coloring matters. 
The ether method yields the best product. The finely cut galls are 
first exhausted with water, at a temperature of 40° or 60° C. (104° 
or 140° F.) ; the infusion is allowed to cool, then filtered and in- 
timately mixed with commercial ether by agitation. When the 
emulsion has separated, the upper ethereal layer, containing coloring 
matter, resin, fat, gallic and ellagic acids, is removed and the aqueous 
fluid, after concentration, under reduced pressure, in a still, to a 
syrupy consistence, is spread, when cool, on tin plates, which are 
placed on a steam table and covered with a wooden box ; this causes 
the tannin to puff up and dry and gives rise to the peculiar spongy 
character of commercial tannin. The so-called crystalline tannic 
acid of German manufacturers is obtained by introducing a very 
thick syrupy mass, prepared as above 1 stated, into well tinned copper 



616 PHARMACEUTICAL CHEMISTRY. 

vessels, with a perforated bottom, through which the mass slowly 
drops in long threads on to heated revolving cylinders, where it 
dries, and is removed in the form of thin needle-shaped particles. 

Another plan is to extract the powdered nntgall with a mixture of 
ether four parts and alcohol one part, transferring the tannic acid to 
water by agitatiou with the latter, and then proceeding as before 
stated. This method is extensively employed. 

Diluted alcohol is used in the preparation of alcohol-tannin by 
percolation, the tincture being concentrated and evaporated to dry- 
ness in a vacuum apparatus. Water-tannin is obtained by evaporat- 
ing the aqueous infusion described above, to dryness, in a vacuum- 
pan. Neither of these products is as free from color or impurities 
as the first named or ether-tannin. 

In 1893 Prof. Trimble suggested the use of acetone for the ex- 
traction of tannic acid from nutgall and exhibited, at Chicago, a 
sample of the acid, almost white, prepared by this method. The ad- 
vantages claimed for this solvent are cheapness, thorough penetra- 
tion, and rapidity of action. 

Glucose, the most persistent impurity found in tannin, can be 
removed completely, as suggested by Trimble, by treatment with 
lead acetate and hydrogen sulphide and subsequent extraction of the 
tanniu with acetic ether. 

Gallotannic acid differs markedly from oak-bark tannins in its 
behavior toward several reagents, thus, while with lime water oak- 
tannins give a pink or red precipitate, gallotannic acid causes a blue 
precipitate ; with bromine water gallotannic acid gives no precipitate, 
while oak-tannins cause a yellow precipitate ; ferric chloride and 
ammonium hydroxide cause a green precipitate with oak tannins 
and a blue one with gallotannic acid, etc. The blue color sometimes 
observed in the case of oak-tannins with ferric salts is due to the 
presence of a foreign substance, pure oak-tannin showing only a 
green color. (Trimble.) 

Owing to the ready discoloration of tannic acid by metallic iron 
in the presence of moisture, all contact with spatulas under such 
conditions must be avoided. Solutions of tannic acid change readily, 
particularly if exposed to air and light, gallic acid and probably 
ellagic acid, C 14 H 8 9 , being gradually formed ; such changes are 
retarded and even prevented by the presence of glycerin or alcohol in 
sufficient quantity. 

The term tannin is now applied to the whole group of vegetable 
astringents, while the name tannic acid has been reserved for the 
particular product derived from nutgalls. The classification adopted 
by Trimble divides all tannins into two main groups, which may be 
distinguished from each other by the reactions above mentioned. 
All tannins should be soluble in water and precipitated by gelatin. 
The gallotannic- acid group includes, besides nutgall tannin, the 
tannins found in chestnut wood, chestnut bark, pomegranate bark, 
and sumac, while the oak-tannin group comprises the tannins from 



OB GANIC A CIDS. 617 

different species of oak, from kino, catechu, krameria, tormentil, 
mangrove, and canaigre. 

While, for technical purposes, the estimation of tannin in various 
tanning materials is often of importance, and is no doubt also valua- 
ble in chemical plant analysis, such determinations are not required 
in pharmacy. Advantage is taken of the well-known property of 
tannin to form insoluble compounds with gelatin (as demonstrated in 
the preparation of leather), and this operation is included in all 
methods of assay thus far published. A complete account of Lowen- 
thal's method for estimating tannin, as modified by Von Schroeder, 
will be found in the National Dispensatory, 5th edit., p. 108. 

Tartaric Acid, H 2 4 H 4 O 6 or (CHOH) 2 (C0 2 H) 2 . This acid is 
even more widely distributed in the fruit of many plants than citric 
acid, occurring both in the free and combined state. For commercial 
purposes, it is obtained from crude or partially purified argols (see 
p. 432) by neutralizing the acid potassium tartrate in hot solution with 
chalk, whereby calcium and potassium tartrates are formed, and then 
decomposing the remaining potassium tartrate with calcium chloride ; 
the resulting calcium tartrate is washed with water until tasteless and 
decomposed by digestion with sulphuric acid, when sparingly soluble 
calcium sulphate is formed and tartaric acid liberated, which latter 
enters into solution. After removal of the precipitated calcium sul- 
phate by filtration, the solution of tartaric acid is concentrated and 
allowed to crystallize, the crystals, if necessary, being redissolved, 
digested with auimal charcoal and recrystallized. 

Tartaric acid is rarely found in the shops in other than powder 
form, and, as a rule, is free from impurities. The official test for 
oxalic and uvic acids, by means of calcium sulphate solution, depends 
upon the insolubility of calcium oxalate anduvate in the presence of 
ammonium salts, whereas calcium tartrate is but slowly deposited 
under like conditions; an excess of ammonia must be avoided, hence 
the Pharmacopoeia directs incomplete neutralization. If crystallized 
tartaric acid is contaminated with uvic acid, the latter is readily de- 
tected by the milk-white appearance of its crystals, those of tartaric 
acid being translucent. 

Valerianic Acid, HC 5 H 9 2 or (CH 3 ) 2 CH.CH 2 .C0 2 H. As 
this acid occurs in a free state in valerian root, it may be obtained 
by distilling the root with water, neutralizing the aqueous portion of 
the distillate with soda, and decomposing this solution with sulphuric 
acid, it may then be purified by fractional distillation. 

Commercially the acid is made by oxidation of amyl alcohol with 
a mixture of potassium dichromate and sulphuric acid,aud neutraliz- 
ing the distillate with sodium hydroxide; the resulting sodium vale- 
rianate is decomposed by means of sulphuric acid, when the liberated 
valerianic acid will rise as an oily layer. This is then freed from 
water by treatment with sulphuric acid, and carefully distilled. 



£18 PHARMACEUTICAL CHEMISTRY. 

The reaction taking place may be illustrated thus : 3C 5 H u OH-^ 
2K 2 Cr 2 7 + 8H 2 SO,= 3HC 5 H 9 2 + 2K 2 S0 4 +2Cr 2 (S0 4 ) 3 +llH 2 0. 
Since a small portion of the amyl alcohol escapes oxidation, it is 
attacked by the newly formed acid and passes over into the distillate 
as a compound ether, known as amyl valerianate, C 5 H n C 5 H 9 2 ; the 
name apple oil is given to this ether, on account of its apple-like odor 
when diluted. When the acid distillate is neutralized with soda the 
amyl valerianate separates as an oily liquid, and may be removed. 

The solubility of valerianic acid in not less than 26, and not re- 
quiring over 30 times its weight of water, affords a ready means of 
discovering certain impurities ; it should also produce a clear solu- 
tion with a slight excess of ammonia water. 

The only use made of valerianic acid in pharmacy is for the pro- 
duction of ammonium valerianate in the manufacture of the elixir of 
the same name. 



CHAPTER LIX. 

ALKALOIDS. 

The name alkaloids is applied to a large class of carbon compounds 
containing nitrogen, which are capable of neutralizing acids and 
forming salts. The basic properties of these compouuds vary in 
intensity, some exhibiting but a feeble basic reaction, while others 
are capable of decomposing heavy metallic salts with the formation 
of metallic hydroxides. The term alkaloid was given to these 
so-called organic bases on account of their similarity in chemical 
character to alkalies, alkaloid meaning alkali-like. 

Since the discovery of basic principles in both living and dead 
animal tissues the name alkaloids has generally been restricted to 
those nitrogenous bases derived from plants, the term leucomaines 
having been selected for the basic substances found in living animal 
tissues and ptomaines for those produced during putrefaction of dead 
animal tissues; the last named are still sometimes called cadaveric 
alkaloids. Chemists go even a step further by subdividing vegetable 
bases and reserving the name alkaloid for all those shown to be 
derived from pyridine, C 5 H 5 N, or quinoline, C 9 H 7 N, two simple 
bases found in coal tar. 

The discovery of alkaloids occurred within the present century, 
in 1817, when Sertiiruer, a German apothecary, demonstrated the 
basic character of a substance obtained by him, in 1806, from opium, 
now known to us as morphine. In order to distinguish the basic 
from neutral vegetable principles a different terminology has been 
adopted for the two classes, which has been maintained in the Phar- 
macopoeia and serves an excellent purpose. The ending ine (Latin 
ina) is applied to all basic plant products, while the ending in (Latin 
inum) is given to all neutral principles. 

Alkaloids may be divided into two main classes as regards their 
constitution, namely, those containing carbon, hydrogen, nitrogen, 
and oxygen, and those containing only the first three elements; to 
the former, which are always solid, the name amides has been given, 
while the latter, which are liquid, are known as amines. Vegetable 
bases do not all possess the same saturating power for, while the 
majority are monacid in their character, several well-defined diacid 
bases are known. When brought together with acids they do not, 
like inorganic bases, cause the displacement of basylous hydrogen 
with the formation of water, but behave like ammonia, forming salts 
by simple addition. In regard to the, naming of salts formed by the 
union of alkaloids with acids, it is customary in the case of oxygen 



620 PHARMACEUTICAL CHEMISTRY. 

acids to follow the usual rule, thus : acetates, citrates, nitrates, phos- 
phates, sulphates, etc., but, in the case of halogen acids, the proper 
name would seem to be obtained by changing the termination ie of 
the acid into ide for the salt, thus hydrobromide, hydrochloride, 
hydrocyauide, etc.; the Pharmacopoeia has, however, adopted the 
plan of using the termination ate throughout, no matter what acid 
is in combination. 

Jn a pure state alkaloids, with a few exceptions, are but sparingly 
soluble in cold water, but dissolve more or less readily in alcohol, 
chloroform, petroleum benzin, benzene, amyl alcohol, etc.; some, but 
not all, dissolve in ether. Salts of the alkaloids, as a rule, are 
soluble in water, but less so in other solvents. 

In nature alkaloids rarely occur in a free state, being usually asso- 
ciated with an acid, which, in some instances, is a peculiar acid 
characteristic of the plant in which it is found, as igasuric acid in 
combination with the alkaloids of nux vomica, quinic acid of the 
ciuchona barks, meconic acid in opium, etc.; many alkaloids occur 
in the plant as tannates. Alkaloids are not always restricted to 
special parts of the plant ; while present to a much larger extent in 
some parts than in others, they are frequently met with in the root, 
stem, leaf, and fruit of the same plant. For their extraction various 
methods are employed : either the finely comminuted drug is 
exhausted with acidulated water, whereby the alkaloid is brought 
into solution as a new salt, which can then be decomposed and pre- 
cipitated by means of an alkali and further purified by resolution in 
some appropriate solvent, filtration through animal charcoal and crys- 
tallization ; or the drug may be exhausted with a neutral solvent, such 
as alcohol or diluted alcohol, the resulting tincture being acidulated, 
evaporated to remove fats, resins, etc., filtered, treated with water, and 
precipitated and purified as stated above. Advantage is taken of the 
difference in solubility between free alkaloids and their salts to sep- 
arate and purify the product by the use of immiscible solvents, such 
as water and petroleum benzin, water and chloroform, water and ether, 
etc., whereby the alkaloid can be alternately transferred, in a com- 
bined or free state, from one fluid to another ; this necessitates, of 
course, provision for bringing the liquids into intimate contact by 
agitators. This method, which is extensively employed in the assay 
of alkaloidal drugs, is termed by analysts the ll shaking out process," 
because, on a small scale, the transfer is made in glass separators by 
rotatiou or shaking. In large operations, such as the manufacture 
of the cinchona alkaloids and others, kerosene or gasolene, closely 
allied to benzin, is now extensively employed on account of its solvent 
capacity, its cheapness, and ready separation from watery fluids. In 
the case of alkaloids which are volatile, the drug is placed in a still 
with some water, and, by the addition of a fixed alkali, the alkaloid 
is liberated, and with the aid of heat, passed over into a receiver 
containing acidulated water, when, having been obtained as an acid 



ALKALOIDS. 621 

salt, it can be further purified and isolated by one of the methods 
before mentioned. 

To determine the presence of an alkaloid in any drug, the simplest 
plan is to macerate a small portion of the finely powdered article 
with about ten times its weight of Prollius' fluid, a liquid of remark- 
able penetrating power, composed of ether 325 Cc, alcohol 25 Cc, 
and stronger water of ammouia 10 Cc. The maceration should be 
conducted in a well-closed flask, for several hours, with frequent 
agitation, after which, some of the clear liquid is decanted into a 
glass separator (see Fig. 138) containing some 5 per cent, sulphuric 
acid, and, by means of careful but active rotation, any alkaloid 
present is transferred to the acid fluid ; upon withdrawing this and 
warming on a water-bath to remove ether and alcohol, the addition 
of any of the general reagents mentioned below will produce a 
cloudiness or precipitate if alkaloids have been extracted. 

Although particular alkaloids are only found in certain plants or 
species of plants, it often happens that several alkaloids are present 
in the same plant, ranging from 2 in nux vomica to 21 in opium 
and 32 in cinchona ; rarely, however, does the number exceed 4. 
When pure, alkaloids are, as a rule, crystallizable, excepting the 
amines or liquid bases, without color, and have a definite melting- 
point, which latter is an important test of purity; their different 
solubilities have already been referred to. In solution, whether 
free or in a combined state, they are precipitated by a number of 
substances which are known as alkaloidal class reagents, and there- 
fore incompatible with them in prescriptions. Such reagents are 
tannic acid, picric acid, mercuric chloride, and iodine with potassium 
iodide; besides these, the following tests for the presence of alkaloids 
are known by special names — Mayer's reagent, a solution of potas- 
sium mercuric iodide (see United States Pharmacopoeia, page 486), 
Mamie's reagent, a solution of potassium cadmium iodide, Dragen- 
dorff's reagent, a solution of potassium bismuth iodide, Scheibler's 
reagent, phosphotungstic acid, Sonnenschein's reagent, phosphomolyb- 
dic acid, and others. Many alkaloids give characteristic color reac- 
tions with acids and other reagents, by means of which their identity 
may be established ; some of these reactions will be mentioned farther 
on in connection with the individual alkaloids. Very complete in- 
formation regarding the behavior of alkaloids toward reagents as 
well as their source, solubilities, etc., is to be found in Sohn's Dic- 
tionary of the Active Principles of Plants (1894). 

The quantitative determination of alkaloids in drugs may be 
effected both gravimetrically and volumetrically. The first method 
is largely employed, and is applicable whenever it is possible to 
isolate the alkaloid in the crystalline form or of any fair degree of 
purity, as in the official process for the morphiometric assay of 
opium or in determinations of cocaine. When, however, the alka- 
loidal residue is accompanied by appreciable quantities of impuri- 
ties, such as coloring and resinous matters, the results obtained by 



622 PHARMACEUTICAL CHEMISTRY. 

the gravimetric method are invariably too high and should be 
checked by volumetric estimation, which is best accomplished by 
solution of the residue in an excess of decinormal hydrochloric or 
sulphuric acid, with the aid of heat and titration of the excess of 
acid by means of centi- or decinormal alkali in the presence of a 
suitable indicator, as explained in the official process for the estima- 
tion of alkaloids in extract of mix vomica. In case but one alka- 
loid is present this method of titration leaves nothing whatever to 
desire, but when several alkaloids occur in a drug, lack of positive 
information as to the relative proportion in which these alkaloids 
are present causes a source of error which analysts thus far have 
not been able to overcome ; in such cases, after careful purification 
of the alkaloidal residues by appropriate means, the gravimetric 
method is probably to be preferred for the determination of total 
alkaloids. The use of Mayer's Solution (decinormal solution of 
potassium mercuric iodide) was at one time advocated for the volu- 
metric determination of alkaloids, on account of the formation of 
definite compounds between alkaloids and the double iodide; but 
since the results obtained have been found to vary with conditions 
not always controllable it has been abandoned, its use being now 
restricted to that of a qualitative reagent. 

The Pharmacopoeia gives specific directions for the determination 
of alkaloids in two drugs — cinchona and opium — and in eight 
galenical preparations — namely, the extract, fluid extract and tinc- 
ture of nux vomica, and the extract, tincture, vinegar and wine of 
opium as well as the tincture of deodorized opium. 

The official assay of cinchona involves the gravimetric determina- 
tion of both total alkaloids and quinine ; the former should reach not 
less than 5 per cent, of the weight of the drug, the latter at least 
2.5 per cent. These percentages are now frequently exceeded in 
commercial cinchonas, barks containing 8 per cent, of total alkaloids 
and from 4 to 6 per cent, of quinine being not unusual ; choice 
cinchona barks with 10 and 12 per cent, of quinine have even been 
found. The determination of the total alkaloids is readily under- 
stood ; the ammonia present in the menstruum liberates the alkaloids, 
which are then taken up by the alcohol-chloroform mixture. Using 
definite proportions of drug and menstruum, an aliquot part of the 
filtrate represents a definite proportion of the drug. The residue of 
crude alkaloids is dissolved in diluted acid and again filtered to remove 
impurities, the filter being washed with acid water so as to recover 
any alkaloids retained in form of solution. The final addition of 
alkali again liberates the alkaloids, which are then taken up by 
repeated treatment with chloroform ; the solution being evaporated 
and the residue dried to constant weight at 100° C. As 10 grammes 
of cinchona are represented in the chloroformic solution, the weight 
of residue multiplied by 10 must express the percentage of total 
alkaloid found. It frequently happens in the evaporation of chloro- 
formic solutions of alkaloids that a varnish-like film is formed, 



ALKALOIDS. 623 

retaining traces of chloroform, hence it is advantageous to redissolve 
this film in a small quantity of ether which, upon being heated and 
evaporated, carries the last chloroform with it, thus insuring greater 
accuracy in weight. 

The determination of quinine depends upon the greater solubility 
of this alkaloid in ether. By evaporating the original solution of 
alkaloids in the presence of powdered glass, the residue is obtained 
in a divided condition, in which it is readily acted upon by any sol- 
vent, hence, if treated with ether, this liquid will quickly dissolve 
any quinine present and as much of the other alkaloids as the quan- 
tity of ether used is capable of taking up. If now the residue be 
percolated with another like quantity of ether, the quinine having 
been taken up by the first treatment, a quantity of other alkaloids 
will again be dissolved corresponding to that dissolved by the 
first portion of ether and, by evaporation of this ether solution 
separately, the quantity so dissolved can be ascertained. Subtract- 
ing the weight of the second residue from the weight of residue 
obtained by evaporation of the first ether solution, the weight of the 
quinine dissolved is ascertained. Thus, if 5 Gm. of cinchona are 
represented in the alcohol-chloroform residue as officially indicated, 
and the residue from the first ethereal solution weighs 0.1875 Gm. 
and that from the second 0.0625 Gm., the difference, 0.125 Gm., 
indicates the weight of quinine present, which multiplied by 20 gives 
2.5 as the percentage of quinine contained in the sample. 

The morphiometric assay of opium directed in the Pharmacopoeia 
is generally known as Squibb's method, having been first suggested 
by Dr. E. R. Squibb as a modification of Fliickiger's method. Mor- 
phine, being present in opium chiefly as sulphate, is readily extracted 
with water, but, along with it, other substances, narcotine, codeine, 
coloring-matter, inorganic salts, etc., are also brought into solution, 
which it is proposed to remove entirely or retain in solution by the 
addition of alcohol and ether when the precipitation of the morphine 
is finally effected. As pure morphine is not entirely insoluble in 
water, a dilute mother-liquor is undesirable, hence concentration of 
the infusion is resorted to, in order to reduce the loss from this 
source ; the addition of alcohol has been found advantageous in pre- 
venting the precipitatiou of coloring matter along with the morphine, 
and is by no means hurtful in the proportion directed. The ether 
removes narcotine and codeine, and, moreover, by its saturation of 
the aqueous fluid, still further reduces the solvent power of the latter 
on the freshly liberated morphine. The addition of ammonia water 
decomposes the morphine salt in solution and the free alkaloid grad- 
ually separates in the form of crystals. Morphine crystallizes with 
one molecule (5.94 per cent.) of water, and does not lose this water 
when dried at 60° C. (140° F.), hence, if accurate results are wanted, 
the crystals should be dried at that temperature, since the Pharma- 
copoeia requires results in hydrated crystallized alkaloid. If the 
crystals are dried to constant weight, at 100° or 110° C. (212° or 



624 PHARMACEUTICAL CHEMISTRY. 

230° F.), which is often more convenient than a regulated lower 
temperature, the weight of the anhydrous crystals should be multi- 
plied by 1.063 to correspond to the hydrated crystals. 

If the pharmacopoeial directious be carefully observed, good results 
will almost invariably be secured. The highest percentages are 
generally obtained by allowing the crystals to separate during 
eighteen or twenty hours, but the longer the time the greater the 
impurities deposited aloug with the morphine. During the ordinary 
time allowed, from ten to twelve hours, these impurities are probably 
compensated for by the loss of morphine remaining in the mother- 
liquor, but, beyond this point, a correction often becomes necessary 
either by the lime-water test or ash test ; pure morphine is soluble 
in 100 times its weight of official lime-water, hence, by treating 0.5 
Gm. of morphine with 50 Ce. of lime-water, and ascertaining the 
weight of the insoluble residue when dry, the proportion of impuri- 
ties present can readily be calculated. 

The assay of extract of opium is very similarly conducted, and 
can be performed in less time, owing to the solubility of the extract 
in water. In the case of the tincture of opium it becomes necessary 
to get rid of the resinous and other matter taken up by the hydro- 
alcoholic menstruum ; precipitation with water is therefore directed 
in the Pharmacopoeia. 

The official method of assay for extract of nux vomica is some- 
what similar to that directed for cinchona. The first treatment with 
ammonia water and alcohol liberates the alkaloids and brings these 
into solution, whence they are abstracted by successive treatment 
with chloroform. The residue obtained by evaporation of the chlo- 
roformic solutions is dissolved in hot water, with the aid of a meas- 
ured quantity of decinormal sulphuric acid, which converts the 
alkaloids into sulphates, an excess of acid remaining. After the 
addition of an indicator, centinormal alkali solution is added until 
the appearance of a permanent pinkish color indicates that a very 
slight excess of alkali is present. Centinormal alkali is used in 
preference to a decinormal solution to enable the operator to carefully 
neutralize the excess of acid without the danger of adding a marked 
excess of alkali. In order to bring the alkali solution to the value 
of the decinormal acid, it becomes necessary to divide the number ot 
cubic centimeters of centinormal solution used by 10 ; subtracting 
the quotient so obtained from the number of cubic centimeters of 
decinormal acid first used gives the quantity of j-q H 2 S0 4 neutralized 
by the free alkaloids obtained from the extract. Since two alkaloids 
are known to be present in nux vomica, the neutralizing power of 
both must be taken into consideration in finding the factor indicating 
the value of 1 Cc. of decinormal acid. The proportions in which 
these alkaloids occur vary somewhat, but have been accepted as equal 
by analysts for the present, hence the Pharmacopoeia directs that one- 
half the sum of their molecular weights shall be used, which divided 
by 10,000 yields (334 -j- 394 = 728 ; 728 -*- 2 = 364 ; 364 -*- 



ALKALOIDS. 625 

10,000 = 0.0364) 0.0364 as the amount of total alkaloids represented 
by 1 Cc. of T N q- H 2 S0 4 . As only 2 Gm. of extract are directed to be 
used for the assay, the percentage of alkaloids present may be found 
by multiplying either the number of cubic centimeters neutralized 
by the alkaloids by 1.82 (0.0364 X 50), or the number of cubic cen- 
timeters by 0.0364, and this product, which is the total amount of 
alkaloids in the two Gm., by 50. 

The chemical constitution of absolutely pure alkaloids has been 
the subject of long and deep research. A French book published by 
Professor Pictet, of Geneva, Switzerland, in 1891, contains much 
valuable information along this line ; a German translation by 
TVolffenstein is accessible to those familiar with the latter language. 
During the past four or five years Freund, of Germany, has added 
considerably to the knowledge of the constitution of alkaloids, and 
Wright, Dunstan, Ince, and Short, of England, have also contrib- 
uted the results of their studies. Such investigations may eventu- 
ally lead to the successful synthetic production of numerous natural 
alkaloids, as has already been possible in a few instances. 

The following natural alkaloids are recognized in the Pharmaco- 
poeia in an uncombined state : Atropine, Cinchonine, Codeine, Mor- 
phine, Quinine, Strychnine, and Veratrine. Caffeine, although pos- 
sessing but very feeble basic properties, must nevertheless also be 
placed in this class ; by some authorities it is not considered an alka- 
loid at all, since it is not precipitated by potassium mercuric iodide 
solution and other class reagents. 

Salts of the following natural alkaloids are officially recognized : 
Atropine, Cinchonidine, Cinchonine, Cocaine, Hyoscine, Hyoscya- 
mine, Morphine, Pilocarpine, Physostigmine or Eserine, Quinine, 
Quinidine, Sparteine, and Strychnine ; also salts of the following 
alkaloidal derivatives : Apomorphine, Hydrastinine. 

The Official Alkaloids and Alkaloidal Salts. 

Apomorphine Hydrochloride. C 17 H 17 N0 2 HC1. Apomor- 
phine may be classed among the so-called artificial alkaloids, being 
obtained by the action of hydrochloric acid on morphine or codeine. 
The process consists in heating either alkaloid with about 20 parts 
of pure hydrochloric acid in a sealed tube for several hours in an oil 
bath to between 140° and 150° C. (284° and 302° F.). After cool- 
ing the liquid contained in the tube is diluted with water, when, 
upon the addition of an excess of sodium bicarbonate, apomorphine 
will be precipitated ; the mixture is filtered, and the new alkaloid 
extracted from the residue by means of ether or chloroform. The 
reaction occurring in the case of morphine appears to be simply an 
abstraction of the elements of water ; thus, C 17 H 19 N0 3 — H 2 = 
C 17 H 17 N0 2 ; in the case of codeine, however, an intermediate pro- 
duct is formed, which is further split up into methyl chloride and 
apomorphine, thus, C 18 H 21 N0 3 + HC1 — C 18 H 20 ClNO 2 -f H 2 j 

40 



626 PHARMACEUTICAL CHEMISTRY. 

C 18 H 20 ClNO 2 = C 17 H 17 N0 2 + CH3CI. If a few drops of hydrochloric 
acid be added to the ethereal or chloroformic solution above men- 
tioned, apomorphine hydrochloride will separate in a crystalline 
form, and may be recrystallized from boiling water. The salt must 
be thoroughly dried over sulphuric acid and carefully protected 
against moisture, air, and light, otherwise it soon assumes a green 
color, due to oxidation. 

Apomorphine hydrochloride is always dispensed in the form of 
aqueous solutions, and amber vials should be used for the same; the 
gradual green coloration of the solution can be prevented by addi- 
tion of a few drops of hydrochloric or acetic acid. A solution of 
this salt may be readily distinguished from one of morphine hydro- 
chloride by precipitating the alkaloid with sodium bicarbonate ; the 
amorphous residue, in the case of apomorphine, soon turns green, 
and imparts to its solution in ether a purplish-violet color, and to a 
chloroformic solution a blue color. The alkaloid morphine is in- 
soluble in these liquids. 

Atropine. C 17 H 23 N0 3 . This alkaloid belongs to the class known 
as mydriatic alkaloids, so named on account of their property of 
causing dilatation of the pupil of the eye, which occur in belladonna, 
duboisia, hyoscyamus, scopolia, and stramonium, and include atro- 
pine, belladonnine, hyoscine, and hyoscyamine ; claturine and duboi- 
sine, formerly considered as distinct alkaloids, are now known to be 
identical with atropine and hyoscyamine respectively. Atropine, 
hyoscine, and hyoscyamine have the same percentage composition, 
and the last named can be converted into the first by the action of 
alkalies in alcoholic solution. All three alkaloids are easily decom- 
posed by strong acids and alkalies. 

Atropine is found chiefly in belladonna, being obtained preferably 
from the root, as the latter is richer in alkaloid and free from chloro- 
phyll. The finely powdered root is exhausted with alcohol, and the 
percolate mixed with calcium hydroxide to decompose the natural salt 
of atropine and liberate the alkaloid, which remains in solution ; 
after filtration, the filtrate is acidulated with diluted sulphuric acid, 
concentrated to remove alcohol, fat, and resin, and treated with alkali 
carbonate in excess. The precipitated atropine is removed, washed 
with water, and dissolved in alcohol ; to this alcoholic solution water 
is added, drop by drop, to incipient turbidity, and the alkaloid 
allowed to crystallize. Other bases present remain in the mother- 
liquor, but small quantities of hyoscyamine always accompany the 
commercial article. 

Atropine is a monacid base possessing marked alkaline properties; 
it is capable of decomposing mercuric and mercurous chloride with 
the formation of the respective oxides ; it also reddens phenolphtalein 
paper, and restores the blue color of reddened litmus. 

The melting-point of atropine is incorrectly stated in the Phar- 
macopoeia to be 108° C. (226.4° F.) ; if pure, it melts at 115° C. 



ALKALOIDS. 627 

(239° F.), but this is largely affected by the presence of hyoscyamine, 
which itself melts at 108° C. 

Atropine Sulphate. (C 17 H 23 N0 3 ) 2 H 2 S0 4 . This salt may be 
prepared either by adding atropine slowly to a mixture of sulphuric 
acid and alcohol or by dissolving atropine mixed with water by 
meaus of diluted sulphuric acid. Iu either case a perfectly neutral 
solution must be obtained, which is then evaporated to dryness, at a 
temperature below 40° C. (104° F.). Some of the commercial salts 
show an acid reaction when dissolved in water, and are, therefore, 
unfit for use. 

Caffeine. C 8 H 10 N 4 O 2 -f H 2 0. This feebly basic substance oc- 
curs in a number of plants belonging to different natural orders, 
thus, in coffee, tea, kola, and paullinia, associated with tannin and 
varies in amount from less than 1 to 5 per cent, of the dried material. 
For commercial purposes it is usually obtained from powdered coffee- 
beans, not roasted, or preferably the fine unsalable particles of tea- 
leaves (tea-leaves being also much richer in caffeine), by exhausting 
the same with hot water, adding a solution of lead acetate iu slight 
excess, whereby tannin and coloring- matters are precipitated, filtering, 
adding ammonia water to remove excess of lead salt and again filter- 
ing. The filtrate is concentrated, hydrogen sulphide added to re- 
move any lead still remaining, filtered and further evaporated to the 
crystallizing- point. Milk of lime is also sometimes used to remove 
tannin, fat, coloring-matter, etc., and is added to the powdered 
material, the mixture being then exhausted with warm 80 per cent, 
alcohol ; the percolate is diluted with about one-sixth its volume of 
water and distilled to recover the alcohol. The aqueous residue is 
filtered and crystallized. If necessary, the product is redissolved, 
filtered through bone-black, and again crystallized. 

Caffeine is very soluble in boiling water, 2 parts, and also in 
chloroform, 7 parts, but requires 80 parts of cold water for solution, 
which quantity is very materially reduced, however, by the presence 
of certain other substances, such as sodium benzoate, bromide, sali- 
cylate, and cinnamate, and even antipyrine. 

The caffeine derived from different sources is now considered 
identical, although the names theine and guaranine are still occasion- 
ally used. 

Chemically, caffeine is a derivative of xanthine, as shown by the 
murexide reaction mentioned below, being known as tri methyl 
xanthine, C 5 H(CH 3 ) 3 N 4 2 , and sometimes also called methyl theo- 
bromine. It has been prepared synthetically by the action of methyl 
iodide on theobromine, C 5 H(CH 3 ) 2 ^T 4 2 , a basic substance found in 
cacao beans. 

When treated with chlorine water or hydrochloric acid and potas- 
sium chlorate, as directed in the Pharmacopoeia, caffeine yields, upon 
evaporation to dryness, a substance known as amalic acid, which, in 



628 PHARMACEUTICAL CHEMISTRY. 

the presence of air and ammonia, forms murexoin or tetramethyl 
murexide, C 8 (CH 3 ) 4 N 5 6 (NH 4 ), of a rich purple color ; this test is 
characteristic of catfeine and theobromine. 

Cinchonidine Sulphate. (C 19 H 22 N 2 0) 2 H 2 S0 4 + 3H 2 0. Cin- 
chonidine is one of the four important alkaloids found, among a 
large number (32), in cinchona bark and occurs in greater proportion 
in the so-called red bark, derived from cinchona succirubra, than in 
others. The sulphate is obtained from the mother-liquors left in 
the manufacture of quinine sulphate and is purified by fractional 
crystallization. The official salt, containing but three molecules, 
7.29 -|- per cent., of water of crystallization, is the result of using 
a hot concentrated solution, for, if the salt be crystallized from 
weaker solutions it will contain six molecules, or 14.6 per cent, of 
water. 

Absolute purity of the salt is not practicable, nor demanded by 
the Pharmacopoeia, hence a slight fluorescence is sometimes observed 
in solutions of the salt made with diluted sulphuric acid. The 
official test with Rochelle salt and ammonia water depends upon 
the insolubility of cinchonidine tartrate, the tartrates of cinchonine 
and quinidine being dissolved and reprecipitated upon addition of 
ammonia. 

Cinchonine. C 19 H 22 N 2 0. This base is present in all cinchona 
barks and may be obtained from the mother- liquors of quinine sul- 
phate, by precipitating these, after dilution, with ammonia or soda, 
and dissolving the resulting precipitate in boiling alcohol, when 
upon cooling cinchonine will separate in a crystalline form, being far 
less soluble in cold alcohol than the other alkaloids present. If boil- 
ing alcohol be used for the extraction of the mixed bases in the 
manufacture of quinine sulphate, cinchonine will also crystallize 
from this upon cooling. In either case the alkaloid may be purified 
by resolution and recrystallization. 

Pure cinchonine, like pure cinchonidine, shows no blue fluor- 
escence in a solution made with sulphuric acid, nor is either alkaloid 
appreciably soluble in ether. They differ from each other in their 
optical rotation, cinchonine being dextrorotatory and cinchonidine 
laevorotatory. 

Cinchonine Sulphate. (0 19 H 22 N 2 O) 2 H 2 SO 4 + 2H 2 0. The 
usual process for making this salt is to dissolve the alkaloid cincho- 
nine in warm diluted sulphuric acid until the acid is neutralized and 
then concentrate and crystallize the solution. The Pharmacopoeia 
requires the absence of more than 5 per cent, of water of crystalliza- 
tion. Cinchonine sulphate may be readily distinguished from cin- 
chonidine sulphate by its greater solubility in chloroform, requiring 
not oyer 80 parts for solution, while the latter requires about 1320 



ALKALOIDS. 629 

Cocaine Hydrochloride. C 17 H 21 N0 4 .HC1. The leaves of ery- 
throxylon coca contain a number of basic principles, all derivatives of 
ecgonine, C 9 H 15 N0 3 , of which cocaine is the most important ; other 
non-crystallizable bases are truxilline or isatropylcocaine (known 
also as cocamine), C 19 H 23 N0 4 , hygrine, C 12 H 13 N, and cinnamyl- 
cocaine, C 19 H 23 N0 4 . Cocaine appears in the plant united with coca- 
tannic acid. The processes employed for the isolation of cocaine are 
usually guarded as secrets by manufacturers, and it is known that 
large quantities of the alkaloid are now prepared synthetically, owing 
to the difficulty of extracting pure cocaine in remunerative quan- 
tities from the drug. 

When finely powdered coca leaves are moistened with solution of 
sodium hydroxide and then treated with petroleum ether, kerosene, 
or gasolene, the alkaloids present are liberated and taken up by the 
menstruum, from which they can be transferred, as salts, to diluted 
sulphuric acid, through intimate contact by agitation. If to this 
acid solution solution of soda be added in excess, cocaine mixed with 
some of the lesser alkaloids will be precipitated, the bulk of the 
hygrine, however, remaining in solution ; the crude cocaine may be 
removed by filtration and expression and purified by crystallization 
from alcohol. As the yield of cocaine is known to decrease mate- 
rially by transportation, no doubt owing to decomposition, the result 
of fermentation in the imperfectly dried and tightly packed leaves, 
the bulk of the natural alkaloid is now manufactured in South 
America, in places adjacent to the source of gathering the leaves, 
processes of extraction very similar to the above being employed. 

In order to avoid loss of the decomposition-products and other 
alkaloids accompanying cocaine in the crude article, the pure alka- 
loid is now extensively prepared by synthesis, in the following man- 
ner, which is possible, since the chemical constitution of cocaine 
is definitely known to be methyl benzoyl ecgonine. Boiling the 
mixed bases with hydrochloric acid converts them all into ecgonine, 
C 9 H 15 N0 3 , and if ecgonine hydrochloride, C 9 H 15 N0 3 HC1, be dis- 
solved in methyl alcohol and the solution treated with dry hydro- 
chloric acid gas, hydrochloride of methyl ecgonine, C 9 H U CH 3 X0 3 HC1, 
will be formed and can be crystallized from an alcoholic solution. 
By heating this latter compound with benzoyl chloride, C 7 H 5 0C1, in 
a water-bath, until hydrochloric acid is no louger evolved and a 
homogeneous mass results, cocaine is obtained, which is freed from 
benzoic acid by solution in water, filtration, precipitation of the 
alkaloid with ammonia and recrystallization from alcohol. Synthetic 
cocaine is identical in every respect with the natural alkaloid. 

Cocaine hydrochloride is prepared by dissolving the pure alkaloid 
in alcoholic solution of hydrochloric acid and crystallizing the anhy- 
drous salt, which latter only is recognized in the Pharmacopoeia. 

The two most important tests for the purity of the salt are those 
with potassium permanganate and with hot hydrochloric acid ; the 
former, given in the Pharmacopoeia, depends upon the stability of 



630 PHARMACEUTICAL CHEMISTRY. 

cocaine permanganate. If pure cocaine hydrochloride be carefully 
warmed in a test-tube with about four times its weight of strong hy- 
drochloric acid, until the mixture begins to boil, a colorless solution 
results ; the degree of color, if there be any, is, in a measure, an 
indication of the amount of impurities present; the color thus ob- 
tained should never exceed that of a pale wine tint. 

Codeine. C 18 H 21 N0 3 + H 2 0. This alkaloid is obtained from 
opium, where it exists to the extent of from J to j per cent, along 
with morphine, by treatment of an aqueous infusion of opium with 
chalk and calcium chloride, whereby codeine and morphine hydro- 
chlorides are formed and can be purified by repeated crystallization. 
If a solution of these crystals be treated with ammonia, morphine 
will be precipitated while codeine remains in solution and may be 
recovered by crystallization ; if potassa or soda be used in place 
of ammonia, codeine will be precipitated, the morphine remaining 
in solution. 

Codeine crystallizes from an aqueous solution with one molecule 
(5.67 per cent.) of water, which constitutes the official article ; if 
crystallized from ether or carbon disulphide, it is anhydrous. Its 
crystals are larger and more soluble in water than those of any other 
alkaloid. Although the free alkaloid only is recognized in the Phar- 
macopoeia, the sulphate and phosphate of codeine are largely used by 
physicians; they can be prepared by neutralizing an aqueous solution 
of the alkaloid with the respective acid and crystallizing. 

Chemically, codeine is closely allied to morphine, as shown by the 
formula, C 17 II 18 CH 3 N0 3 , which differs from that of morphine by a 
methyl group, hence the name methyl morphine. When heated 
with strong hydrochloric acid, in a sealed tube, both alkaloids yield 
apomorphine, but, if heated to 180° C. (356° F.) with a concen- 
trated solution of zinc chloride, codeine yields apocodeine, whilst 
morphine again yields apomorphine. Codeine has been prepared 
synthetically by heating morphine with methyl iodide. The name 
codeine is derived from the Greek word xcbosta, meaning head, re- 
ferring to the source of the alkaloid, poppy heads. 

Hydrastinine Hydrochloride. C u H 11 N0 2 HC1. The alka- 
loid hydrastinine does not occur in any plant, but is an artificial base 
obtained by oxidation of hydrastine — the white alkaloid found in 
hydrastis — in acid solution, by means of potassium dichromate or 
permanganate. Since the use of this basic principle and its salts is 
very limited, it seems particularly strange that the Pharmacopoeia 
should have failed to recognize hydrastine, which is far more ex- 
tensively employed, and yet have given prominence to one of its 
derivative products. 

This salt differs from hydrastine hydrochloride in being colored; 
its aqueous solution is not affected by ammonia water, while hydras- 
tine is precipitated from a solution of its salts under like circumstances. 



ALKALOIDS. 631 

Hyoscine Hydrobromide. C 17 H 21 N0 4 HBr-f3H 2 0, or C 17 H 23 - 
N0 3 HBr-j-3H 2 0. Hyoscine is an amorphous alkaloid, occurring in 
the plants belonging to the natural order of the Solanaceae, associated 
with hyoscyamine and atropine. It is fouud in largest quantity, about 
-g- 1 ^ or -g 1 ^- per cent., in the seed of hyoscyamus and the leaves of the 
duboisia. For commercial purposes hyoscine is obtained from either 
of the above sources, chiefly henbaue seed, by exhausting the drug 
with 80 per cent, alcohol, recovering the alcohol by distillation and 
setting the residue aside for several days, when a fatty layer separates 
from the aqueous solution of the mixed bases in combination with 
organic acids. By addition of alkali carbonate to the aqueous solu- 
tion, the alkaloids are liberated and may be abstracted by agitation 
with ether. Upon evaporation of the ether a syrupy liquid is 
obtained, from which nearly all the hyoscyamine. present crystallizes 
out ; the hyoscine may be isolated from the mother-liquor by con- 
verting it into an aurochloride, separating the same by fractional 
crystallization, redissolving in water, and, after removal of the gold 
by means of hydrogen sulphide, precipitating the hyoscine from the 
filtrate, by alkali carbonate, in the form of an oily layer, which may 
be purified by solution in chloroform and evaporation of the solvent. 
When perfectly pure, hyoscine occurs as a tenacious syrupy mass. 
No doubt manufacturers employ a less expensive method of separating 
hyoscine from hyoscyamine, but guard it as a secret. 

The official salt may be obtained by dissolving hyoscine in a very 
slight excess of diluted hydrobromic acid, concentrating the solution 
and allowing it to crystallize. It contains about 1 2.5 per cent, of water. 

Although the Pharmacopoeia has adopted for hyoscine the formula 
of Hesse and Schmidt, C 17 H 2l N0 4 , Ladenburg and other authorities 
give it as C 17 H 23 N0 3 , making the alkaloid isomeric with atropine 
and hyoscyamine. 

Hyoscyamine Hydro-bromide. C 17 H 23 N0 3 HBr. The method 
for obtaining the alkaloid hyoscyamine has been outlined in the pre- 
ceding article. The hydrobromide may be prepared like the cor- 
responding salt of hyoscine, but forms anhydrous crystals. 

Hyoscyamine Sulphate. (C 17 H 23 N0 3 ) 2 H 2 S0 4 . This salt is 
obtained by dissolving hyoscyamine in sufficient diluted sulphuric 
acid to form a neutral solution, which, after proper concentration, is 
allowed to crystallize. Both this and the preceding salt may be dis- 
tinguished from the corresponding salts of atropine by forming, upon 
addition of gold chloride test-solution and recrystallization of the 
precipitate from boiling-water, minute, lustrous, golden-yellow scales, 
while the atropine salts yield crystals forming a yellow, lustreless 
powder, on drying. 

MoRPHrxE. C 17 H 19 N0 3 -f-H 2 0. This is the most important of 
the large number of alkaloids found in opium, and, as before stated, 



632 PHARMACEUTICAL CHEMISTRY. 

was the first basic principle isolated from plants. It was called by 
its discoverer morphium, after the Greek deity Mofxpsu^, the God of 
sleep, on account of its sleep-producing properties. 

Morphine is present in opium in varying quantities, reaching as 
high as 12 or 14 per cent, in some samples of commercial opium not 
dried ; the Pharmacopoeia recognizes no undried opium containing 
less than 9 per cent, of morphine and demands from 13 to 15 per 
cent, in the powdered article. It was formerly supposed to exist 
in combination with meconic acid only, but is now known to be 
present largely, if not altogether, as sulphate. 

Morphine for commerce may be obtained in several ways ; the 
natural salts being soluble in cold water, opium is exhausted with 
this menstruum, and the infusion, after concentration, treated either 
with sodium carbonate or with chalk and calcium chloride; the 
latter process is preferable, since meconic acid and coloring-matters 
are precipitated as lime compounds, while the alkaloids are converted 
into soluble chlorides. After filtration the filtrate is concentrated, 
and yields a crystalline mass of morphine and codeine chlorides ; 
narcotine remains in solution in the dark-colored mother-liquors ; 
the crystals are purified by resolution in water, filtration through 
animal charcoal, and recrystallization. Finally, the mixed salts are 
dissolved in water and decomposed by addition of ammonia water, 
whereby the morphine is precipitated, the codeine remaining in solu- 
tion. The morphine is subsequently recrystallized from hot alcohol. 
Other methods are known, and manufacturers, probably in each case, 
follow some favorite process. 

The alkaloid morphine is rarely used in pharmacy, except in the 
preparation of the various oleates of morphine. The official article 
contains about 5.94 per cent, of water of crystallization, which it 
readily loses at 110° C. (230° F.), but parts with very slowly at the 
temperature of a boiling-water bath. Owing to the solubility of 
morphine in solutions of the fixed alkali hydroxides and insolubility 
in ether, as well as its characteristic reactions with oxidizing agents, 
it is readily distinguished from other alkaloids. 

Morphine Acetate. C 17 H 19 N0 3 C 2 H 3 2 -f 3H 2 0. This salt is 
prepared by dissolving the alkaloid morphine in a slight excess of 
diluted acetic acid and evaporating the solution to dryness with the 
aid of a moderate heat, so as to avoid decomposition. It never occurs 
in a crystalline form on the market, but always in powder form. 
Morphine acetate is easily decomposed by heat or exposure to air, 
and the partial insolubility of the salt sometimes observed is due to 
such change, caused either by carelessness during evaporation of the 
solution or exposure to air and light ; when such a condition exists 
a drop or two of diluted acetic acid should be added to produce per- 
fect solution. This salt is preferred by Germau practitioners of 
medicine, while in Great Britain the hydrochloride is given the 



ALKALOIDS. 633 

preference, and in this country the sulphate ; of the three salts, the 
acetate is the most soluble in water. 

Morphine Hydrochloride. C 17 H 19 N0 3 HC1 -f 3H 2 0. By 
using dilute hydrochloric acid as a solvent for morphine alkaloid a 
solution of this salt is obtained, which, upon coucentration, yields 
well-defiued crystals containing 14.38 per cent, of water ; an excess 
of acid should be avoided, as the salt is very stable and must have 
a neutral reaction. As made in this country, morphine hydrochloride 
occurs in large masses of feathery crystals, and is more bulky, weight 
for weight, than the sulphate. It can be rendered perfectly anhy- 
drous at a temperature of 100° C. (212° F.). 

Morphine Sulphate. (C 17 H 19 N0 3 ) 2 H 2 S0 4 - + 5H 2 0. Next to 
quinine sulphate there is probably no alkaloidal salt more extensively 
used by physicians than this one, and, unfortunately, its unauthor- 
ized use among the laity is on the increase in this country, owing to 
the lack of sufficient legal restrictions and the cupidity of certain 
pharmacists and dealers in drugs. Like the two preceding salts, 
morphine sulphate is made from the alkaloid by dissolving the same 
in sufficient diluted sulphuric acid to form a neutral solution and 
setting this aside to crystallize. The official salt contains 11.87 per 
cent, of water of crystallization, of which, however, only a part, 7.12 
per cent., can be expelled at the temperature of a boiling- water bath. 

An aqueous solution of morphine sulphate is largely used in some 
parts of this country under the name 31agendie , s Solution ; it con- 
tains 16 grains of the salt in each fluidounce, which is equal to about 
-^=0 of a grain in each minim. As aqueous solutions of morphine 
sulphate do not keep well for any length of time, one-half grain of 
salicylic acid has been used in each fluidounce of this solution with 
excellent results. Prior to 1880, a solution of morphine sulphate 
was officially recognized in the Pharmacopoeia ; this solution con- 
tained only one grain of the salt in each fluidounce, and must not 
be confounded with Magendie's solution. 

Physostigmine Salicylate. C 15 H 2l N 3 2 C 7 H 6 3 . The alkaloid 
physostigmine occurs in calabar beans to the extent of rarely more 
than one-tenth of one per cent., and its isolation requires considerable 
care, owing to its ready decomposition. The usual method of extrac- 
tion is to exhaust the powdered bean with 85 per cent, alcohol, 
and concentrate the tincture in a vacuum apparatus to a syrupy 
consistence; the resulting extract separates into an upper layer, 
consisting of fat, etc., and a lower, aqueous solution of the natural 
salts of the alkaloids. By treating the aqueous layer with sodium 
bicarbonate, and then repeatedly shaking with ether, the liberated 
physostigmine may be extracted ; the ethereal solution is next treated 
with diluted sulphuric acid, so as to obtain a solution of the alkaloid 
as sulphate, leaving impurities, fat, resin, etc , in the ethereal liquid. 



634 PHARMACEUTICAL CHEMISTRY. 

The pure alkaloid is finally obtained by decomposing the sulphate 
with sodium bicarbonate, extractiug again with ether and crystal- 
lizing. Heat must be avoided as far as possible, also the use of 
strong alkalies, as in the case of the mydriatic and other easily decom- 
posable alkaloids. 

The name eserine, by which physostigmine is also known, was 
derived from the word esere, meaning split nut, the name applied 
by the African negroes to the calabar bean. Calaberine is the name 
given to another alkaloid present in the beau, which, however, is 
insoluble in ether. 

Physostigmine salicylate may be prepared by neutralizing a solu- 
tion of the alkaloid in absolute alcohol with pure salicylic acid ; the 
salt gradually separates in needle-shaped crystals, free from color, 
which can be then drained and dried. 

Some of the salts of physostigmine and their aqueous solutions 
readily assume a reddish color when exposed to light and air, hence 
they must be dispensed in tightly closed amber vials ; the name 
rubereserine has been given to the red substance thus formed. The 
salicylate is less liable to change by exposure to light than the other 
salts ; but, owing to its slight solubility in water, is far less used 
than the sulphate. 

Physostigmine Sulphate. (C 15 H 2l N 3 2 ) 2 H 2 S0 4 . The prepara- 
tion of this salt has already been indicated above in connection with 
the extraction of the alkaloid from the drug ; by carefully neutral- 
izing an alcoholic solution of physostigmine with sulphuric acid and 
concentrating the solution to a syrupy liquid, at moderate tempera- 
ture, crystals of the salt may be obtained. The commercial article 
is rarely entirely free from color, generally occurring in yellowish, 
amorphous, very hygroscopic masses. 

This aud the preceding salt are used, in the form of solution and 
gelatin disks, for the purpose of producing myosis or contraction of 
the pupil of the eye. 

Pilocarpine Hydrochloride. C n H 16 N 2 2 HCl. Pilocarpus 
or jaborandi leaves contain three alkaloids, of which only one, how- 
ever, is of pharmaceutical interest — namely, pilocarpine, which 
occurs in variable quantities, often not exceeding one-half per cent. 
It may be extracted by means of alcohol acidulated with hydro- 
chloric acid ; the resulting tincture is concentrated, when resin, fat, 
etc., separate, the remaining liquid is treated with ammonia water 
and the liberated alkaloids extracted by repeated agitation with 
chloroform, the chloroform ic solution being evaporated to a syrupy 
consistence and neutralized with nitric acid, the resulting nitrates 
being taken up with alcohol, from which the pilocarpine nitrate 
crystallizes while the nitrates of pilocarpidine and jaborine remain 
in solution; by dissolving the crystals in water, adding ammonia 
water in excess and shaking the mixture with chloroform, pure pilo- 



ALKALOIDS. 635 

carpine may be obtained as a colorless syrupy liquid upon evapora- 
tion of the chloroform solution. 

The hydrochloride is prepared by neutralizing the alkaloid with 
dilute hydrochloric acid aud evaporating the resulting solution to 
dryness, when it is obtained as a crystalline powder. 

The salts of pilocarpine are used chiefly as diaphoretics and 
sialagogues, but possess also decided myotic properties, like physos- 
tigmine. 

Quinidine Sulphate. (C 20 H 24 N 2 O 2 ) 2 H 2 SO 4 +2H 2 O. Quini- 
dine usually remains in the mother-liquors from the crystallization 
of quinine sulphate, from which it may be obtained by adding a 
large excess of ammonia water, whereby cinchonine and ciuchoni- 
dine are thrown down, while quinidine remains in solution ; it can 
subsequently be precipitated by means of caustic soda and dissolved 
in diluted sulphuric acid, the resulting salt being purified by recrys- 
tallization. From the purified alkaloid, obtained by precipitation 
with soda, the sulphate can be readily prepared by solution in just 
sufficient warm diluted acid to neutralize the same, and crystallizing; 
if an excess of acid be used, a salt differing from the official salt will 
be formed. 

Quinidine sulphate somewhat resembles official quinine sulphate 
in appearance, and has some chemical properties in common with it, 
but may be distinguished by its greater solubility in water and in 
alcohol and by being precipitated in concentrated aqueous solution 
by potassium iodide. Its solutions, like those of quinine sulphate, 
form thalleioquin and show a blue fluorescence when acidulated 
with sulphuric acid. 

Quinine. C 20 H 24 K,O 2 -[-3H 2 O. This is, no doubt, the most 
important and extensively used of all alkaloids. It occurs to a 
varying extent in the different species of cinchona, the yield having 
increased greatly with careful cultivation of the trees in India, Java, 
etc. The bases present in cinchona bark exist in combination with 
quinic or kinic, quinovic, and cinchotannic acids, and are usually 
extracted by means of acidulated water. The infusion is concen- 
trated and mixed with milk of lime, whereby the alkaloids are 
liberated while the calcium compounds of the organic acids are pre- 
cipitated together with much coloring-matter. By straining the 
mixture and exhausting the residue repeatedly with boiling alcohol, 
amyl alcohol, petroleum benzin or kerosene, a solution of the crude 
alkaloids is obtained, from which the latter may be transferred as 
sulphates by treatment with dilute sulphuric acid. Another plan is 
to mix the powdered bark with solution of soda or milk of lime, 
whereby the natural combinations are broken up and the alkaloids 
liberated ; the mixture is then exhausted, in a suitable apparatus, 
with hot alcohol or kerosene, from which, after proper concentration, 
the alkaloids are extracted as acid sulphates by means of sulpuhric acid. 



636 PHARMACEUTICAL CHEMISTRY. 

In either case the acid solution is treated with animal charcoal, 
and the liquid, while hot, after nitration, neutralized with solution 
of soda, when, upon cooling, neutral quinine sulphate crystallizes out 
and may be purified by resolution, recrystallization, etc. The other 
alkaloids, including also small quantities of quinine sulphate, remain 
in the mother-liquor and may be recovered as stated elsewhere. 

From the purified quinine sulphate the alkaloid may be obtained 
by precipitation with soda, after solution of the salt in water with 
the aid of an acid. 

Official quinine alkaloid contains about 14.3 per cent, of water of 
crystallization and melts at a comparatively low temperature, 57° C. 
(134.6° F.) ; at 100° C. (212° F.), about two-thirds of the water is 
expelled, but it does not become anhydrous until a temperature of 
125° C. (257° F.) is reached. The commercial article varies con- 
siderably in appearance and solubility, due, no doubt, to different 
methods of manufacture; some is crumbly, compact, and idioelectric, 
dissolving slowly in alcohol and even dilute acids, while another lot 
is light, possesses no electric tendency, and dissolves readily. 

The test for appreciable quantities of other cinchona alkaloids 
depends upon the greater solubility of quiniue alkaloid in ammonia 
water, 0.5 Gm. of the freshly precipitated alkaloid being soluble in 
7 Cc. of 10 per cent, ammonia water at 15° C. (59° F.). The in- 
creased quantity of ammonia water allowed by the Pharmacopoeia 
in case the maceration of the quinine sulphate with water has 
been made at a temperature above 15° C. (59° F.) is necessary, since 
a greater quantity of the salt will have been dissolved. In the offi- 
cial test the residue left upon drying the mixture of quinine, am- 
monium sulphate, and water consists chiefly of quinine sulphate, 
thus j 2C 20 H 2 AO 2 +(NH 4 ) 2 SO 4 =(C 20 H 2 ,N 2 O 2 ) 2 H 2 SO 4 +2NH 3 . 

Quinine Bisulphate. C 20 H 24 N 2 O 2 H 2 SO 4 -j-7H 2 O. When neu- 
tral quinine sulphate is dissolved in water with the calculated neces- 
sary quantity of sulphuric acid an acid salt will be formed, which can 
be obtained of the above composition by crystallization. Its solution 
in water shows a strong blue fluorescence and has a strong acid reac- 
tion. The salt contains a larger proportion of water of crystilliza- 
tion, 23 per cent., than other quinine salts, which it loses if heated 
to the temperature of boiling water. 

Quinine Hydrobromide. C 20 H 24 N 2 O 2 HBr-l-H 2 O. This salt, 
also known in commerce as quinine bromide, can be made by dis- 
solving the alkaloid quinine in warm diluted hydrobromic acid until 
neutralized and crystallizing the solution. It has also been obtained 
by double decomposition between an aqueous solution of potassium 
bromide and a warm alcoholic solution of quinine sulphate, the 
resulting potassium sulphate being precipitated, while the quinine 
hydrobromide is subsequently recovered by crystallization from a 
concentrated solution. 



ALKALOIDS. 637 

Quinine hydro-bromide has been largely used for hypodermic 
medication. 

Quinine Hydrochloride. C 20 H 24 N 2 O 2 HCl-j- 2 H 2 O. Like the 
preceding salt, quinine hydrochloride can also be made by double 
decomposition, but is usually obtained by dissolving the alkaloid 
quinine in sufficient diluted hydrochloric acid to form a neutral solu- 
tion and allowing this to crystallize. This salt differs from other 
quinine salts in being the most soluble in water and in the absence 
of the usual blue fluorescence from concentrated solutions unless 
acidulated with sulphuric acid; an excess of hydrochloric acid does 
not affect it. It is commonly called muriate of quinine by dealers. 

Quinine Sulphate. (C 20 H 24 N 2 O 2 ) 2 H 2 SO 4 .+ 7H 2 0. The offi- 
cial salt is the neutral sulphate, although termed by some basic sul- 
phate ; it is also known as quinine disulphate, but this term is 
incorrect and should not be used, diquinine sulphate indicating the 
true chemical composition. The manufacture of this most important 
alkaloidal salt has already been explained in connection with the 
preparation of quinine alkaloid. In order to insure a large yield of 
the salt it is necessary that the hot solution from which it is to crys- 
tallize be of a neutral reaction ; the sulphates of the other alkaloids 
present are all far more soluble in cold water than quinine sulphate, 
and will, therefore, almost wholly remain in the mother-liquors. 
Small quantities of the lesser alkaloids are no doubt always present 
in the commercial article, but should not be detectable by the official 
test with ammonia water ; the United States Pharmacopoeia fixes no 
percentage limit of impurities, which in the British Pharmacopoeia is 
placed at 5 per cent. 

The official test with ammonia water, known as Kernels test, de- 
pends upon the greater solubility of the sulphates of the other cin- 
chona alkaloids in cold water and the greater solubility of quinine 
alkaloid in ammonia water. DeVrij and Schaefer have shown that 
as much as 10 or 12 per cent, of lesser cinchona alkaloids may escape 
detection by Kerner's test, hence the German Pharmacopoeia has 
adopted a modification by Kerner and Weller, which consists in digest- 
ing in a test tube 2 Gm. of quinine sulphate dried at 40° or 50° C. 
(104° or 122° F.) with 20 Cc. of distilled water at 60° or 65° C. 
(140° or 149° F.) for 30 minutes, with frequent agitation. The tube 
and contents are then cooled and kept at a temperature of 15° C. 
(59° F.) for two hours, with frequent agitation, after which the mix- 
ture is filtered ; 5 Cc. of the filtrate should yield a clear solution with 
4 Cc. of 10 per cent, ammonia water. This test is much more severe 
than that of the United States Pharmacopoeia, and demands a much 
purer salt. Whenever solutions of alkaloidal salts are filtered it 
should be borne in mind that filter paper abstracts appreciable 
quantities of the salt from solution ; it should, therefore, either be 
filtered through glass wool or the filtrate through paper should be 



638 PHARMACEUTICAL CHEMISTRY. 

collected in fractions of 5 Cc. each., of which the second or third 
fraction only should be used for the above test. 

Chemically pure quinine sulphate has been offered for sale for 
some time. This is obtained by first preparing pure quinine bisul- 
phate by repeated recrystallization, and then exactly neutralizing a 
hot aqueous solution thereof with sodium carbonate, when, upon 
cooling, pure quinine sulphate will crystallize out. 

The most convenient test for chemically pure quinine sulphate is 
either Schaefer's test with potassium oxalate or DeVrij's test with 
potassium chromate ; both depend upon the very sparing solubility 
of the respective quinine salts. Schaefer's test is made as follows : 
1 Gm. of official or 0.85 Gm. of anhydrous quinine sulphate is dis- 
solved in 35 Cc. of distilled water by means of heat in a small flask 
previously tared ; a solution of 0.3 Gm. of crystallized neutral potas- 
sium oxalate in 5 Cc. of water is then added, the contents of the 
flask made to weigh 41.3 Gm. by addition of distilled water, and the 
mixture kept at a temperature of 20° C. (68° F.) for thirty minutes, 
with occasional agitation. 

After nitration one drop of solution of soda added to 10 Cc. of 
the nitrate should produce no turbidity within 3 or 5 minutes. Less 
than 1 per cent, of other cinchona alkaloids can be detected by this 
method. 

Quinine sulphate can be crystallized with varying proportions of 
water, the official salt being allowed as much as 16.18 per cent. As 
the salt effloresces upon exposure, the symbolic formula given in the 
Pharmacopoeia representing 14.43 -j- per cent, of water probably 
indicates the average composition of the commercial salt. Very 
appreciable loss of weight has been observed in cases where the salt 
was preserved in simple paper boxes, hence manufacturers now use 
either glass or tightly sealed tin containers. 

The emerald-green color mentioned in the Pharmacopoeia as occur- 
ring when a dilute aqueous solution of the quinine sulphate is mixed 
with a little bromine water and an excess of ammonia water is due 
to the formation of a resinous body to which the name thalleioquin 
(from the Greek word &&XXb<z, a green branch) has been given. 
Chlorine water may be used in place of bromine water, but, accord- 
ing to Fliickiger, the latter is more sensitive, detecting as little as 1 
part of quinine in 20,000 of solution. The thalleioquin reaction is 
characteristic of quinine salts, but is also obtained with quinidine. 

Quinine Valerianate. C 20 H 24 N 2 O 2 .HC 5 H 9 O 2 -f H 2 0. This 
salt may be conveniently prepared by dissolving freshly precipitated 
quinine alkaloid in warm water by means of valerianic acid and 
crystallizing the solution upon cooling. It is decomposed at the 
temperature of boiling water, losing valerianic acid. 

Sparteine Sulphate. C 15 H 26 N 2 H 2 S0 4 +4H 2 O. Sparteine is 
the only alkaloid belonging to the class of amines recognized in the 



ALKALOIDS. 639 

Pharmacopoeia. It is a liquid heavier than water and has been 
obtained by extracting scoparius with water acidulated with sulphuric 
acid, concentrating the infusion, decomposing the salt with sodium 
hydroxide and distilling. The distillate is supersaturated with 
hydrochloric acid, evaporated to dryness and distilled with the aid 
of potassa ; first ammonia passes over, after which sparteine distils 
and condenses as a thick oily liquid. Another method consists in 
exhausting the powdered drug with 60 per cent, alcohol, evaporating 
the tincture at a low temperature and extracting the alkaloid with 
the aid of tartaric acid ; the solution of sparteine tartrate is then 
decomposed with potassium carbonate, and the alkaloid thus liber- 
ated abstracted with ether. Pure sparteine is a colorless fluid, boiling 
at 287° C (548.6° F.) and having an aniline-like odor and intensely 
bitter taste. It is easily decomposed upon exposure to air and light. 
Sparteine sulphate is prepared by neutralizing the purified alkaloid 
with diluted sulphuric acid and rapidly concentrating the solution, 
when colorless crystals will be obtained. As indicated by the official 
formula it is the salt of a diacid base. The Pharmacopoeia recog- 
nizes the presence of 4 molecules (17.8 per cent.) of water of crystal- 
lization, which represent about the average commercial products, as 
the amount of water varies from 3 to 5 per cent. 

Strychnine. C 21 H 22 N 2 2 . This alkaloid occurs in combination 
with igasuric acid, generally associated with brucine, in the Strych- 
nos Xux vomica and other members of the natural order Logan- 
iacese. The proportion of strychnine present in the seed varies, 
sometimes reaching as high as 1.8 per cent. 

To extract the alkaloids the powdered drug may be exhausted with 
boiling water acidulated with hydrochloric or sulphuric acid, whereby 
the igasuric acid is liberated and the alkaloids obtained in solution 
as hydrochlorides or sulphates. Upon concentration of the infusion 
and addition of milk of lime the alkaloids are precipitated, and by 
collecting upon a strainer and washing the residue with water much 
foreign matter is removed. Subsequent treatment of the residue 
with cold diluted alcohol removes brucine, the treatment being con- 
tinued as long as the washings are reddened by nitric acid, after 
which boiling alcohol is used to extract the strychnine ; this, after 
recovery of the alcohol, is converted into sulphate by solution in 
diluted sulphuric acid, filtered through animal charcoal and precip- 
itated with an alkali. 

Some manufacturers exhaust the drug with hot alcohol of about 
60 per cent., concentrate the tincture, filter and add lead acetate, 
whereby the igasuric acid is removed together with coloring-matters, 
while the alkaloids remain in solution as acetates. After a second 
filtration the alkaloids are precipitated by ammonia and may be 
further treated as above or dissolved in hot alcohol, from which the 
strychnine will crystallize on cooling^ and may be freed from adher- 
ing brucine by washing with diluted alcohol. 



640 PHARMACEUTICAL CHEMISTRY. 

Commercial strychnine occurs both in the form of crystals and 
powder, the latter being preferred for dispensing purposes. Its taste 
is so intensely bitter that it is perceptible if but |- grain be dissolved 
in 10 gallons of water. 

The blue color obtained when strychnine is added to a solution of 
potassium dichromate and sulphuric acid is due to an oxidation-pro- 
duct, the exact nature of which is unknown, as it has not been possible 
to isolate the blue compound on account of its evanescent character. 

Strychnine Sulphate. (C 21 H 22 N 2 O 2 ) 2 H 2 SO 4 +5H 2 0. This 
salt is best prepared by dissolving the alkaloid strychnine in warm 
diluted sulphuric acid, avoiding an excess of the latter; if a hot 
saturated solution be obtained, the salt will crystallize with 5 mole- 
cules (about 10.5 per cent.) of water, as required by the Pharma- 
copoeia. It represents about 78 per cent, of the alkaloid and is 
generally employed for solutions on account of its greater solubility. 

Veratrine. The substance recognized, both in the Pharma- 
copoeia and commercially, by the name veratrine, is a mixture of 
alkaloids obtained from cevadilla seed. It consists of 3 crystallizable 
alkaloids, cevadine, C 32 H 49 N0 9 ; sabadine, C 29 H 51 N0 8 , and sabadin- 
ine, C 27 H 45 N0 8 ; and 2 amorphous alkaloids, known as veratrine, 
C 37 H 53 NO n , and cevadilline or sabadilline, C 34 H 53 N0 9 ; of these ceva- 
dine is the most important. Veratrine is not found in white or green 
hellebore, but other alkaloids, jervine, C 26 H 37 N0 3 , and veratroidine, 
C 51 H 78 N 2 16 , have been isolated from these plants. 

The mixture of alkaloids in cevadilla seed being very complex, no 
attempt is made at separation in the process of extraction, the crushed 
seed being exhausted with alcohol, which dissolves the alkaloids in 
their natural combination with veratric acid. The tincture is con- 
centrated, mixed with water to remove fat and other impurities, and, 
after filtration, precipitated by ammonia in excess. The precipitate, 
having been washed with water, is dissolved in diluted hydrochloric 
or sulphuric acid, the solution decolorized with bone-black and the 
mixed alkaloids again precipitated by an alkali. 

Owing to its intensely irritating effect upon the mucous membranes 
care is necessary in handling veratrine, and dampening with alcohol 
or expressed oil of almond will be found desirable when mixing it 
with other substances. Veratrine is rarely used internally, but 
mostly as oleate or ointment. 

Besides the foregoing there are a number of alkaloids and alka- 
loidal salts not recognized in the Pharmacopoeia, which are of more 
or less interest to pharmacists, and will, therefore, be briefly con- 
sidered. 

Aconitine. C 34 H 47 NO u . This alkaloid is the active principle 
of aconite root, in which it exists combined with aconitic acid. It 



ALKALOIDS. 641 

is usually extracted by means of alcohol acidulated with tartaric 
acid, and, after dilution of the tincture with water, removal of fat, 
resin, etc., by suitable methods, the alkaloid is precipitated by addi- 
tion of sodium bicarbonate and dissolved in ether, from which it 
crystallizes. The investigations of Freund and Dunstan have re- 
cently thrown much light on the constitution of this alkaloid, which 
occurs in the drug to the extent of 0.2 or 0.3 per cent. Commercial 
aconitine is very rarely pure, being accompanied by aconine and 
other products, no doubt because it is easily split up by the action of 
heat and alkalies ; six samples recently examined contained from 61.1 
to 87 per cent, of pure alkaloid. Aconitine, when pure, should be 
completely soluble in ether, and to prepare it on a small scale aconi- 
tine nitrate may be dissolved in water, decomposed with sodium 
bicarbonate and shaken out with ether, from which it will crystallize 
upon spontaneous evaporation of the solvent. It melts at 197° C. 
(386.6° F.). 

Berberine. C 30 H lr N~O 4 . The chief interest attached to this 
alkaloid arises from the fact that, while the alkaloid is soluble in 
water, its salts are difficultly soluble, aud are deposited in a crys- 
talline form from acid liquids. Berberine occurs in several plants — 
in hydrastis to the extent of 3 or 4 per cent. — from which it may be 
obtained by adding to a concentrated aqueous infusion of the drug 
hydrochloric or sulphuric acid in excess, when the corresponding 
berberine salt will be deposited in crystals, which, after purification 
by recrystallization from boiling water, may be decomposed by 
means of freshly prepared lead hydroxide. After filtration and con- 
centration of the filtrate, berberine will separate as a yellow crystal- 
line powder. 

Cixchoxijdixe Salicylate. C 19 H 22 N 2 0.HC 7 H 5 O 3 . This salt, 
which has been used extensively by physicians, may be prepared by 
direct union of the alkaloid and acid. A neutral solution should be 
made in hot water or diluted alcohol and allowed to crystallize upon 
cooling ; the salt is sparingly soluble in cold water. 

Coniine. C 18 H ir N". Couium owes its medicinal virtues entirely 
to the volatile alkaloid, which is present in the unripe fruit (prob- 
ably combined with malic acid), to the extent of 0.5 or 0.8 per cent. 
It can be extracted by exhausting the drug with water acidulated 
with acetic acid, evaporating the iufusion down to an extract, in a 
vacuum apparatus, adding an alkali carbonate aud distilling. By 
collecting the distillate in diluted sulphuric acid, coniine sulphate is 
at once formed, which may be freed from the accompanying ammo- 
nium salt by treatment with alcohol and ether, in which the latter is 
insoluble ; by addition of an alkali to the alcohol and ether solution 
and distillation, couiine will be isolated, aud may be dissolved in 
ether, from which it can be obtained as hydrochloride, by passing 

41 



642 PHARMACEUTICAL CHEMISTRY. 

dry hydrochloric acid gas into the solution, the salt being insoluble 
in ether. Coniine hydrochloride occurs in white crystals, which are 
non-deliquescent, may be dried at 100° C. (212° F.) without decom- 
position, and are soluble in water and alcohol. 

Coniine belongs to the amines, and has been prepared synthetically 
by Ladenburg; it has a strong alkaline reaction and a penetrating, 
suffocating odor. When pure it is a colorless, oily liquid, lighter 
than water, and boiling at 169° C. (336.2° F.). 

Cornutine. This alkaloid, having been but recently isolated, has 
not yet been sufficiently studied to give a full account of its composi- 
tion, properties, etc. According to Keller and others, both the par- 
turient and haemostatic effects of ergot reside in this basic principle, 
which appears to be present in varying quantities in the different 
commercial varieties of ergot. It is soluble in ether, and has been 
obtained in long, colorless, needle-shaped crystals. Keller claims 
that picrosclerotine, ergotinine, and the cornutine extracted by him 
are identical, the former two representing impure forms of the 
latter. As characteristic reactions of the alkaloid, he mentions the 
following two: 1. If a solution of cornutine in concentrated sul- 
phuric acid be allowed to stand for several hours, it will assume a 
violet- blue color. 2. If a drop of ferric chloride solution be added 
to a solution of the alkaloid in sulphuric acid, an intense orange-red 
color is produced, which, upon standing, gradually changes to bluish- 
green and finally to violet. 

Hydrastine. C 21 H 21 N0 6 . This body must not be confounded 
with the mixture of resinoid substances sold under a similar name, 
hydrastin. The alkaloid, hydrastine, occurs in the root of hydrastis 
canadensis, golden seal, associated with berberine, and in commerce 
is frequently designated as the white alkaloid of hydrastis. Exactly 
how hydrastine exists in the drug was, for a long time, uncertain, 
some authorities contending that it is combined with an acid, and 
others that it exists free. According to recent investigations (Sep- 
tember, 1895) by Dohme and Engelhardt, a portion of the alkaloid, 
about 20 per cent, of the total yield, exists in a free state, the 
remainder being in combination with an acid, the nature of which 
has not yet been determined. While formerly supposed to be present 
only in small proportions, hydrastine has now been shown to occur 
to the extent of 2.33 per cent, in the fresh or 3.14 per cent, in the 
dried root. 

In extracting hydrastine for commercial purposes, it becomes 
necessary first to remove the berberine, as stated under that alkaloid ; 
the residuary liquors, after concentration and dilution with water to 
remove resins, fat, etc., are precipitated with ammonia in excess, 
whereby crude hydrastine is separated, which may be purified by 
resolution in diluted sulphuric acid, reprecipitation by means of 
ammonia, and repeated crystallization from hot alcohol. 



ALKALOIDS. 643 

Hydrastine is a weak base melting at 135° C. (275° F.), which, 
while readily soluble in acidulated water, forms difficultly crys- 
tallizable salts. It is extensively used in preparing the so-called 
" colorless hydrastis," which is a solution of the alkaloid in a mixture 
of water and glycerin with the aid of hydrochloric or sulphuric acid. 

Morphine Meconate. (C 17 H 19 N0 3 ) 3 H 3 C 7 H0 7 . This salt is 
not used in medicine, but, under the name " Solution of Bimeconate 
of Morphine," the British Pharmacopoeia recognizes a preparation 
made by precipitating a solution of nine grains of morphine hydro- 
chloride with ammonia water, and, after washing the resulting pre- 
cipitate of morphine, dissolving it in a mixture of one-half fluid- 
ounce of alcohol and one and one-half Huidouces of distilled water 
with the aid of six grains of meconic acid. 

Narcotine. C 22 H 23 N0 7 . This substance occurs in opium, 
sometimes to the extent of 10 per cent, and over. Being readily 
soluble in chloroform and ether, it is easily extracted from powdered 
opium by maceration or percolation with either of these solvents, 
and is, therefore, not found in two official preparations of the drug, 
namely, deodorized opium and tincture of deodorized opium. Nar- 
cotine is a very weak base and does not neutralize acids ; it exists in 
opium in a free state, and, although it forms crystallizable com- 
pounds with hydrochloric and sulphuric acids, these are readily de- 
composed by an excess of water, and yield narcotine to both ether 
and chloroform when shaken with these liquids. A solution of 
narcotine in sulphuric acid soon becomes yellow, and, upon heating, 
turns red and finally purple. 

Pilocarpine Nitrate. C n H 16 N 2 2 .HN0 3 . This salt, which is 
preferred by some to the hydrochloride, may be obtained by neutral- 
izing a solution of pilocarpine with nitric acid and crystallizing. It 
is recognized in the British Pharmacopoeia. 

Quinine Salicylate. C 20 H 24 N 2 O 2 .HC 7 H 5 O 3 . This salt may 
be prepared by neutralizing an alcoholic solution of quinine with 
salicylic acid and allowing the solution, after concentration, to crys- 
tallize ; it can also be obtained, as a curdy precipitate, by mutual 
decomposition between solutions of quinine hydrochloride and ammo- 
nium salicylate, which can be dissolved in alcohol and crystallized 
in an anhydrous state. 

Quinine Tannate. C 20 H 24 N 2 O 2 (C u H 10 O 9 ) 2 . Although tannic 
acid is known to precipitate quinine from a neutral solution of its 
salts in water, this compound is intentionally used by physicians on 
account of its very sparing solubility, which renders its bitter taste 
less perceptible. The salt is usually prepared by adding a solution 



644 PHARMACEUTICAL CHEMISTRY. 

of 1.8 parts of tannic acid in 18 parts of water to a solution of 1 
part of quinine sulphate in 30 parts of water, made with just suffi- 
cient sulphuric or preferably acetic acid. Any excess of acid is 
carefully neutralized with ammonia and the precipitate allowed to 
subside, then washed on a filter w T ith water, being afterward dried 
at a very moderate heat. Quiniue tanuate is officially recognized in 
the German Pharmacopoeia. 



CHAPTER LX. 



NEUTRAL PRINCIPLES AND GLUCOSIDES. 

Besides organic acids and alkaloids, plants furnish a number of 
valuable principles which have a neutral reaction, and, for conveni- 
ence, are divided into bitter principles and glucosides, the former 
being also known as amaroids. The distinguishing feature of the 
latter class is, that when treated with diluted acids or ferments they 
split up into glucose, and a new body, differing from the original 
article acted upon, but characteristic of that substance. With very 
few exceptions, glucosides do not contain nitrogen. Although gluco- 
sides are an important group of plant-products, only one is officially 
recognized in the Pharmacopoeia, partly due to the fact that they do 
not always constitute the active principle of the plant, and are in 
many cases associated with other bodies. A few glucosides appear to 
have a dual character, for, while yielding glucose by the treatment 
above mentioned, some also possess basic and others acid properties. 
As stated in the previous chapter, both glucosides and bitter prin- 
ciples are distinguished from alkaloids by the ending in or inum. 

The following official neutral principles are used by physicians to 
a greater or less extent : aloin, chrysarobin, elaterin, glycyrrhizin, 
picrotoxin, salicin, and santonin ; of these, salicin is a true glucoside. 

Aloin. The name aloin is used, both commercially and in the 
Pharmacopoeia, to designate the neutral, crystalline principle upon 
which the activity of aloes depends, irrespective of the source, 
although the Pharmacopoeia does specify two varieties, namely, that 
derived from Barbadoes and Socotra aloes. The names barbaloin, 
socaloin, and nataloin are used to designate the aloins obtained from 
different sources, which may also be distinguished by special tests. 
It is probable that barbaloin constitutes the bulk of the commercial 
aloin. Cape aloes has thus far not yielded any crystallizable sub- 
stance, but a yellow flocculent precipitate may be obtained by addi- 
tion of bromine to an aqueous infusion. 

Aloin, being wholly soluble in water, is usually obtained by treat- 
ing aloes with hot water, to which a little hydrochloric or sulphuric 
acid has been added ; after the infusion has been allowed to stand for 
a day, it is carefully decanted from sediment, concentrated at a moder- 
ate temperature and set aside, when crystals or crystalline crusts of 
aloin will separate. The aloin may then be purified by recrystal- 
lization from hot water or very dilute alcohol. The addition of a 
little acid has been found advantageous in avoiding the contamination 



646 PHARMACEUTICAL CHEMISTRY. 

of aloin with non-crystallizable matter, which is less soluble in acidu- 
lated water than in plain water. 

This process is well adapted for the manufacture of barbaloin, but 
for socaloin the powdered drug is preferably mixed with a little 
diluted alcohol and strongly expressed, after which the residue (press- 
cake) is dissolved in warm, weak alcohol, and the solution allowed to 
crystallize. Nataloin differs from the other two in beiug sparingly 
soluble in cold and hot water, and must be extracted by treatment 
with hot alcohol, after the drug has previously been treated with 
water ; it can be recrystallized from methyl alcohol, in which it is 
readily soluble. It is rarely found on the market. 

Aloin of commerce is often contaminated with resinous and other 
matter, which can be detected by imperfect solubility of the sample 
in cold water. As stated in the Pharmacopoeia barbaloin differs 
from socaloin in yielding with cold nitric acid a crimson color ; heat 
must not be used in this test, as socaloin, when heated with nitric 
acid, gives similar results. 

Chrysarobin. This principle, derived from Goa Powder by 
treatment with hot beuzene, is frequently confounded in commerce 
with chrysophanic acid. As thus obtained it is still contaminated 
with some impurities, but corresponds to the requirements of the Phar- 
macopoeia ; it can be obtained pure, in the form of small yellow 
scales, by repeated crystallization from acetic acid, and then has the 
composition C 30 H 26 O 7 . By oxidation chrysarobin is gradually con- 
verted into chrysophanic acid, C 15 H 10 O 4 , which latter substance forms 
deep-red solutions with the alkalies ; the change of color mentioned 
in the Pharmacopoeia as occurring when chrysarobin dissolved in 
potassa solution is exposed in a test-tube is due to the formation of 
this acid by absorption of oxygen from the air. 

Elaterin. C 20 H 28 O 5 . Commercial elaterium owes its medicinal 
virtues to a neutral principle called elateriu, which may be extracted 
by treatment with chloroform and subsequent addition of ether to 
the chloroformic solution, whereby crystals of elateriu are precipitated, 
being practically insoluble in ether. The crystals may be further 
purified by washing them with a little ether and recrystallizing from 
chloroform. The yield of elaterin varies from 25 to 35 per cent, of 
the weight of elaterium, and the two substances must not be con- 
founded with each other. 

Glycyrrhizin. This substance, although for a long time con- 
sidered to be a neutral principle and also a glucoside, is now looked 
upon as a tribasic acid, glycyrrhizic acid, having the composition 
C 44 H 63 N0 18 , which exists in liquorice root in combination with am- 
monia as an acid salt. It possesses no medicinal properties, and is 
valuable only on account of its very sweet taste. It is recognized in 
the Pharmacopoeia in combination with ammonia as ammoniated gly- 



NEUTRAL PRINCIPLES AND GLUOOSIDES. 647 

cyn-hizin, and, in the official process for the preparation of this com- 
pound, the complete extraction of glycyrrhizin from the drug is 
insured by adding ammonia water to the menstruum, so that a 
neutral ammonium glycyrrhizate may be formed. The addition of 
sulphuric acid to the percolate causes the precipitation of the gly- 
cyrrhizin, which, for the purpose of purification, is collected, redis- 
solved in ammonia water, aud again precipitated, being finally 
dissolved in sufficient ammonia water and obtained in scales by 
spreading the solution on glass and drying. When boiled with 
diluted sulphuric acid pure glycyrrhizin splits up into glycyrrhetin, 
C 32 H 47 N0 4 , and parasaccharic acid, C 6 H 10 O 8 , which latter reduces 
Fehling's solution like glucose and thus gave rise to the former view 
that glycyrrhizin was a glucoside. 

Pickotoxin. C 30 H 34 O 13 . The neutral principle present in coccu- 
lus can be obtained by exhausting the bruised seed with hot alcohol, 
concentrating the tincture to a thick syrupy consistence, removing 
separated fat and boiling the residue with water. After filtration of 
the decoction picrotoxin will crystallize upon cooling of the filtrate, 
and may be purified by recrystallization from alcohol. 

Salicin. C 13 H 18 7 . Several methods are in use for the extraction 
of this principle from willow and other barks. The bark may be 
macerated and boiled with milk of lime, the decoction, after strain- 
ing, being allowed to subside ; the clear liquid is concentrated, treated 
with animal charcoal and evaporated to dryness, after which the 
residue is exhausted with weak alcohol, from which the salicin will 
crystallize after removal of the alcohol by distillation. Another 
plan is to exhaust the bark with boiling water and deprive the decoc- 
tion of coloring matter and tannin by digestion with litharge or 
treatment with basic lead acetate ; any free acid present in the liquid 
is neutralized with chalk. The filtrate, on concentration, will yield 
crystals of salicin, which may be purified by recrystallization. 

Salicin is the only true glucoside officially recognized. When 
boiled with diluted sulphuric acid it takes up water and splits up 
into glucose and saligenin or salicyl alcohol, thus, C 13 H 18 7 -|-H 2 0= 
C 6 H 12 6 -fC 7 H 8 2 . 

A characteristic reaction of salicin is the production of a bright 
red color when the substance is dissolved in concentrated sulphuric 
acid, followed by the separation of a dark-red powder upon addition 
of water, the solution becoming colorless. The production of the 
fragrant odor of the oil of meadow sweet when salicin is heated with 
diluted sulphuric acid and potassium dichromate also serves to dis- 
tinguish this substance from others ; the odor is due to the forma- 
tion of salicyl aldehyde. 

Santonin. C 15 H 18 3 . Chemically santonin is the anhydride of a 
weak acid, although generally looked upon as a neutral substance. 



648 PHARMACEUTICAL CHEMISTRY. 

It is obtained by mixing ground wormseed with slaked lime and 
exhausting the mixture with hot water; the resulting solution of 
calcium santoninate is concentrated and decomposed with hydro- 
chloric acid. The crude santonin is treated with diluted ammonia 
water, dissolved in alcohol, and the solution decolorized with bone- 
black, after which it is allowed to crystallize. 

Santonin possesses the property of turning yellow when exposed 
to the light and then forms a yellow solution with alcohol, from 
which, however, it again crystallizes colorless. 

The following may be mentioned as characteristic reactions of 
santonin : a bright pinkish-red color is produced when santonin is 
added to an alcoholic solution of potassa ; if 0.010 Gm. of santonin 
be added to a mixture of 1 Cc. each of sulphuric acid and water 
a colorless solution is obtained, which, when heated, assumes a violet 
color upon addition of one drop of ferric chloride solution. 



CHAPTEE LXI. 

ANIMAL FERMENTS. 

Among the digestive agents found in the animal body, two have 
received recognition in the Pharmacopoeia. It is well known that 
the digestion of food is of a twofold character ; one takes place after 
the food has entered the stomach and is called gastric or peptic 
digestion, the other, occurring after the partly digested food leaves 
the stomach, is known as pancreatic or intestinal digestion. During 
the mastication of food it becomes mixed with the secretion of the 
salivary glands, which contains a substance known as ptyalin, be- 
longing to the class of unorganized ferments usually termed enzymes 
by physiologists, from the Greek word enzymos, meaning fermented. 
The special action of ptyalin appears to be to prepare starchy food 
for subsequent digestion, as it is capable of converting starch into 
dextrose ; in the presence of hydrochloric acid even as weak as 0.4 
per cent., it is rendered inert, being most active in slightly alkaline 
liquids. 

The action of ferments upon food depends upon the character of 
the latter, as the different ferments have specific functions and cannot 
be used indiscriminately for all kinds of food. Food partaken of by 
animals is either albuminoid or amylaceous in its nature, the former 
being converted into peptones, the latter into sugars. The digestive 
action of ferments on albuminoids is called the proteolytic action, 
from the word proteolysis, meaning the change occurring in proteids 
while being digested ; the digestion of amylaceous food, on the other 
hand, is known as the amylolytic action of ferments, from amylolysis, 
meaning the conversion of starch into sugar. 

The various products formed during the digestion of food are 
syntonin, albumoses, and peptones. The first, also known as acid 
albumin, is probably produced by the action of hydrochloric acid (of 
which gastric juice contains from 0.1 to 0.25 per cent.) on albumi- 
noid substances, and occurs soon after the ingestion of food. After 
peptic digestion has set in albumoses are formed, which are gradu- 
ally converted into peptones, the end-products of digestion and the 
form in which albuminoid food is assimilated, peptones being readily 
diffusible and absorbed by a process of dialysis. As stated before, 
digestion is not completed in the stomach ; the mixture of albumoses 
and peptones, forming a smooth, pulpy mass called chyme, passes 
into the intestines, where the conversion into peptones and other 
diffusible products is completed. , 

Pancreatin and pepsin are the two agents secreted in the body of 



650 PHARMACEUTICAL CHEMISTRY. 

all animals, without which assimilation of food would be impossible ; 
both have been recognized in the Pharmacopoeia and are largely used 
by physicians. 

Pancreatin. By this name is recognized a mixture of enzymes 
found in the pancreatic juice, the secretion of a gland deeply seated 
in the abdomen, known as the pancreas. The pancreatic juice is 
a clear, colorless, somewhat viscid liquid of an alkaline reaction, 
without odor aud of an insipid, somewhat saline taste ; it possesses 
both proteolytic and amylolytic activity, besides being capable of 
emulsifying fatty matter. 

The Pharmacopoeia gives no directions for the preparation of 
pancreatin and different manufacturers probably pursue different 
methods. The following was suggested in the first edition of the 
National Formulary : Fresh pancreas of the hog, freed as much as 
possible from fat and adhering membranes, is reduced to a fine 
paste by means of a suitable mincing-machine ; it is next mixed 
with half its weight of cold water and kneaded thoroughly aud fre- 
quently during one hour, after which the mass is transferred to a 
strainer and forcibly expressed ; the liquid is filtered as quickly as 
possible through flannel, and to the filtrate is added an equal volume 
of alcohol ; the precipitate is collected, drained, and freed by pressure 
from as much of the adherent liquid as possible ; it is then spread 
on shallow trays, dried by exposure to warm air at a temperature 
not exceeding 40° C. (104° F.) and reduced to powder. When 
large quantities of pancreas are operated upon it is advisable to use 
water saturated with chloroform, which will retard decomposition 
for a long time. 

In some instances the finely minced pancreas is macerated with 
highly diluted hydrochloric acid, in place of plain water, and the 
fat is often removed from the powdered mass by means of purified 
benzin. 

There are supposed to be no less than four unorganized ferments 
present in the pancreatic juice — namely, trypsin, for the digestion of 
albuminoids ; amylopsin, for carbohydrates ; steapsin, for fats ; and 
a rennet ferment, which coagulates milk. Trypsin has been isolated 
in a comparatively pure state ; it differs from pepsin in several im- 
portant particulars, acting best in an alkaline medium, and, although 
active in a neutral or even faintly acid solution, it is completely de- 
stroyed in acid liquids even as weak as gastric juice. Amylopsin 
very closely resembles diastase and ptyalin, both in action and 
properties, though in converting starch iuto maltose aud dextro- 
glucose it is much more energetic than ptyalin. Steapsin, or fat- 
digesting ferment, appears to exert a special action in the emulsifica- 
tiou of fats and more particularly in the presence of the alkali salts 
of the biliary acids, thus preparing them for better absorption. The 
milk-curdling ferment is probably identical with that found in the 
stomach. 



ANIMAL FERMENTS. 651 

Paucreatin usually appears in the form of a yellowish, yellowish- 
white, or grayish-white powder, or in that of transparent, brittle, 
yellowish scales, which are odorless or have a faint, peculiar, not un- 
pleasant odor, and a somewhat meat-like taste. It is slowly and 
almost completely soluble in water, but insoluble in alcohol. 

Pancreatin digests albuminoids and converts starch into sugar, in 
presence of alkalies ; prolonged contact with acids renders it inert. 
It is hygroscopic, and, when exposed to the air for some time, loses 
its value; hence it should be preserved in well-stoppered bottles. 
Dilution with sugar of milk seems to retard deterioration, saccha- 
rated pancreatin having been found to retain its peptonizing value 
tar better than the pure article. The aqueous solution of pancreatin 
is a clear, pale-yellowish liquid, which is precipitated by heat, by 
alcohol, and by hydrochloric acid, but not by a saturated solution of 
sodium chloride. 

Although the proteolytic value of commercial pancreatin is prob- 
ably the most important (as shown by the Pharmacopoeial test), yet 
its action on carbohydrates should likewise be observed. Some 
samples have been found to peptonize milk very readily, and yet 
exert little or no effect on starch-paste, and vice versa. For testing 
pancreatin a 5 per cent, starch muciiage is better suited than a 
stronger preparation, and the length of time required for the com- 
plete conversion of starch into sugar should be noted ; usually, good 
pancreatin is supposed to convert six or eight times its weight of 
starch in a few minutes, the test being conducted at a temperature of 
43.3°-46.1° C. (110°-115° F.). The fact that pancreatin liquefies 
starch-paste is not sufficient, as this may be due to the simple change 
of the starch into dextrin ; a little of the liquid should be added to 
water every few minutes and tested by means of a drop or two of 
some very dilute iodine water ; as soon as the purplish or pinkish 
color fails to appear, the conversion into sugar is complete. The 
less the time required for this change the better is the quality of the 
pancreatin. 

Pepsix. This ferment was discovered in 1836, by Schwann, 
after Eberle had furnished proof that digestion of food in the stomach 
is due neither to the mechanical action of the mucous membranes 
nor to the solvent action of acids, but is dependent upon some un- 
organized ferment present in the gastric juice; this ferment was 
determined by Schwann and named pepsin, from the Greek word 
Tzktptc, (digestion). Pepsin is a secretory product of certain glands 
imbedded in the tissue of the inner coating of the stomach, but has 
also been found in muscular tissue, urine, brain, and the mucous 
membrane of the intestines. True or active pepsin probably does 
not exist at all times in the gastric juice, but is formed by the action 
of hydrochloric acid and chlorides from a mother-substance known 
as pepsinogen, as the digestive functions of the stomach may require; 
in support of this theory it has been found that glycerin will abstract 



652 PHARMACEUTICAL CHEMISTRY. 

increased quantities of pepsin from the mucous membrane of the 
stomach after this has been treated with 0.2 per cent, hydrochloric 
acid, or 1.0 per cent, sodium chloride solution. The use of pepsin 
in medicine is mainly due to the efforts of Dr. Corvisart, court phy- 
sician to the Emperor Napoleon III., but the quality of the com- 
mercial article has been vastly improved since that time ; to the 
perse verence and energy of American pharmacists are due the im- 
provements in the mode of manufacturing pepsin and the wonderful 
increase in digestive power of the commercial article. 

In this country two kinds of pepsin are manufactured, known 
respectively as precipitated pepsin and soluble or scale pepsin ; the 
former is made by the method recommended by E. Scheffer, in 1872, 
which consists in precipitating an acid infusion (prepared cold) of 
clean mucous membrane of hog stomach by a saturated solution of 
sodium chloride, redissolving the precipitate in acid water, reprecipi- 
tatiug with salt in order to purify the pepsin, and finally drying at 
or below 40° C. (104° F.). A full account of this process may be 
found in the American Journal of Pharmacy Toy 1872. The process 
for the manufacture of the so-called scale or peptone pepsins insures 
an increased yield of product and higher digestive power, but not 
always the same degree of purity ; it consists in subjecting the well- 
cleaned mucous membraues of animal stomachs, after being thoroughly 
minced by machinery, to a process of self-digestion in water acidified 
by hydrochloric acid at a temperature of 38°-45° C. (100.4°-113° F.), 
until the whole mass is converted into a uniform, transparent, glairy 
fluid. This is allowed to cool and deposit over night, after an addi- 
tion of chloroform or sulphurous acid solution, which prevents 
putrefaction and in no wise interferes with the activity of the pepsin ; 
the liquid is carefully strained, concentrated in a vacuum apparatus 
to a syrupy consistence, and spread upon plates of glass, where it is 
allowed to scale in suitable dust-free rooms. Pepsin thus prepared 
always contains mucus, peptones, and syntonin, while that prepared 
by the Scheffer method is contaminated with salt and some inert 
albuminous matter. In 1891 a process was patented in this country 
and in England, combining the advantages of the two preceding 
processes. The essential features are as follows : the well-cleansed 
and minced mucous membranes are brought to solution by digesting 
with acidulated water, the solution being clarified after the addition 
of sulphurous acid ; the clear liquid is separated from the deposit 
and then precipitated by saturating, at a higher temperature, with 
sodium sulphate, whereby the pepsin is deposited while the peptone 
remains in solution. The precipitated pepsin is dissolved in weak 
hydrochloric acid and subjected to dialysis, which removes the sodium 
sulphate and remaining peptoues, after which the residual solution is 
concentrated at a low temperature and dried on plates of glass. The 
sodium sulphate is not lost in the process but reclaimed from the 
peptone solution by recrystallization. While the U. S. Pharmaco- 
poeia recognizes only the pepsin obtained from hog stomachs, the 



ANIMAL FERMENTS. 653 

British Pharmacopoeia admits pepsin from the stomachs of hogs, 
sheep, and calves, and gives the following directions for its prepara- 
tion: The stomach of one of these animals recently killed, having 
been cut open and laid on a board with the inner surface upward, 
any adhering portions of food, dirt, or other impurity are to be re- 
moved and the exposed surface slightly washed with cold water ; the 
cleansed mucous membrane is then to be scraped with a blunt knife 
or other suitable instrument, and the viscid pulp thus obtained is to 
be immediately spread over the surface of glass or glazed earthen- 
ware and quickly dried at a temperature not exceeding 100° F. The 
dried residue is to be reduced to powder and preserved in a stoppered 
bottle. 

The official British pepsin is thus seen to consist in part of the 
dried secretion of the mucous membrane, which naturally contains 
substances liable to putrefy, and this, no doubt, accounts for the 
offensive odor noticed in some samples dispensed in this country. 
Such a pepsin also has a w r eak digestive power, and the British Phar- 
macopoeia does not demand that official pepsin shall dissolve more 
than fifty times its weight of hard-boiled egg albumen in thirty 
minutes, at a temperature of 54.4° C. (130° F.). 

French pepsin is chiefly obtained from sheep stomachs, and Bou- 
dault's preparation contains starch and sometimes lactic acid. The 
German Pharmacopoeia does not prescribe the source of official pep- 
sin nor the manner of its preparation ; the stomachs of hogs and 
calves are, however, usually employed. Official German pepsin is 
required to dissolve 100 times its weight of hard-boiled egg albumen 
in one hour, at a temperature of 45° C. (113° F.). 

Pepsin exposed on a watch-glass to the air, even in damp weather, 
should not become sticky in the course of a few hours, showing the 
absence of an undue amount of peptone. It should form, with dis- 
tilled water, an almost clear solution, which is not rendered turbid 
by the addition of acetic acid, showing the absence of mucus. (Pep- 
sin made by Scheffer's process never yields a perfectly clear solution 
with water owing to the presence of syntonin or acid albumin.) It 
should be free. from any disagreeable or ammoniacal odor due to the 
presence of putrescible matter. A drop of tincture of iodine added 
to a solution of pepsin should not develop a blue or purplish-red 
color, showing the absence of starch and dextrin. 

The greater the proportion of peptone present in pepsin the more 
rapidly does it absorb moisture from the air, and the greater the 
absence of mucus the less unpleasant w T ill be the odor and the more 
perfectly clear will be the solution of pepsin in water, especially if 
the water be acidulated with acetic acid. Except in minute quanti- 
ties, sodium chloride impairs the activity of pepsin ; the same is true 
of alcohol. An aqueous solution of pepsin will decompose in a short 
time ; after addition of hydrochloric acid it remains clear but gradu- 
ally loses its effects on albumen. Glycerin, on the other hand, pre- 
serves its virtues. Tannin and the alkali carbonates and bicarbon- 



654 PHARMACEUTICAL CHEMISTRY. 

ates inhibit the proteolytic action of pepsin. At a temperature of 
63° C. (145.4° F.) the activity of pepsin is destroyed. 

The mere solution of hard-boiled egg albumen by pepsin in an 
acid menstruum is by no means an indication of its true value, as 
this can also be effected, under certain conditions, by hydrochloric 
acid and water alone. Complete peptonization or conversion of albu- 
men into peptone appears to be a more positive test, but since the 
exact determination of peptoues in a solution is only possible in the 
hands of the physiological chemist, the different pharmacopoeias have 
adopted a simpler method of valuation. 

Saccharated pepsin, prepared by intimately mixing one part of 
pepsin with nine parts of sugar of milk, is a convenient form of ad- 
ministering small doses of pepsin to children. 



INDEX. 



4 CACIA, 564 
JL mucilage of, 229 

syrup of, 223 
Acetal, 584 
Acetaldehyde, 602 
Acetanilid, 555. 556 
Acetic ether, 576 
Acetoineter, Otto's, 551 
Acetone, 549, 552 

crude, 552 
Acetum opii, 254 

scillse, 254 
Acid, acetic, 549 

crude, 549 
diluted, 551 
glacial, 550 
No. 8, 550 
official, 550 

alphanaphtalenesulphonic, 560 

amalic, 627 

arabic, 564 

arachic, 588 

arsenous, 526 

benzene metadisulphonic, 556 

benzenesulphonic, 557 

benzoic, 607 

synthetic, 603 

betanaphtalenesulphonic, 560 

boric, 418 

carbolic, 557 
crude, 557 
synthetic, 557 

cerotic, 589 

chlorauric, 542 

chloronitrous, 423 

chrysophanic, 546 

cinchotannic, 635 

citric, 608 

copaivic, 606 

crotonolic. 589 

digallic, 615 

ellagic, 616 

erucic, 588 

ethylsulphuric, 457 

gallic, 611 

gallotannic, 615 

glycerylsulphuric, 592 

glycyrrhizic 646 

guaiaconic, 606 

hippuric, 608 

hydriodic, 412 



Acid, hydrobromic, diluted, 419 
hydrochloric, 420 

diluted, 420 
hydrocyanic, diluted, 609 

Scheele r s, 610 
hydroferrqcyanic, 609 
hypophosphorous, diluted, 421 
igasuric, 620, 639 
kinic, 635 
lactic, 612 
lauric, 588 
linoleic, 590 
meconic, 612 
melissic, 589 
metaboric, 419 
metarabic, 565 
mucic, 570 

naphtalenesulphonic, 560 
nitric, 421 

diluted, 422 
nitrohydrochloric, 422 

diluted, 423 
nitromuriatic, 422 
oleic, 588, 613 
orthophenolsulphonic, 453 
oxalic, 613 
palmitic, 588 
paraphenolsulphonic, 453 
pectosic, 565 
phenolsulphonic, 453 
phosphoric, 423 

diluted,. 425 
podophyllinic, 606 
pyrogallic, 611 
pyroligneous, 549 
quinic, 620, 635 
quinoyic, 635 
saccharic, 570 
salicylic, 613 
sarcolactic, 612 
sulpho-ricinoleic, 592 
sozoiodolic, 586 
stearic, 615 
sulpho-carbolic, 453 
sulpho-oleic, 592 
sulphoyinic, 457 
sulphuric, 425 

aromatic, 426 

diluted, 427 
, sulphurous, 427 
tannic, 615 



656 



INDEX. 



Acid, tartaric, 617 

tetraboric, 419 

trichloracetic, 551 

uvic, 617 

valerianic, 617 
Acids, 417 

inorganic, 417 

organic, 607 
Acidum arsenosum, 522 
Aconitine, 640 
Acrolein, 590 
Adeps, 190 

lanse hydrosus, 191 
iEther bromatus, 583 
Alcohol, 571, 573 

absolute, 573, 574 

amyl, 574 

denaturated, 553 

deodorized, 573 

diluted, 573, 574 

ethyl, 571 

methyl, 549, 552 

wood, 549, 552 
Aldehyde, 581 

acetic, 581 

allyl, 590 

benzoic, 598 

cinnamic, 599 

ethylic, 581 
Alkaloids, 619 

cadaveric, 619 

determination, 621 

extraction, 620 

liquid, 619 
Aloe purificata, 269 
Aloin, 645 

Alpha-naphthol, 560 
Alum, 482 | 

ammonium, 482 

ammonio-ferric, 493 

burnt, 483 

chrome, 482 

copper, 534 

crude, 482 

dried, 483 

ferric, 493 

iron, 482 

potassium, 482 
Arumen, 482 

exsiccatum, 482 
Alumini hydras, 482 

sulphas, 482 
Aluminum, acetate, solution, 484 

hydrate, 483 

hydroxide, 483 

naphtolsulphonate, 560 

sulphate, 483 
Alumnol, 560 
Amaroids, 645 
Amides, 619 
Amidin, 562 
Amidobenzene, 556 
Amines, 619 



Ammonia liniment, 380, 381 
camphorated, 381 

spirit, 466 

aromatic, 466 

water, 464 

stronger, 465 
Ammonii benzoas, 461 

bromidum, 461 

carbon as, 461 

chloridum, 461 

iodidum, 461 

nitras, 461 

valerian as, 461 
Ammonium, acetate, solution, 466 

alum, 482 

benzoate, 461 

bicarbonate, 467 

bromide, 461 

carbamate, 462 

carbonate, 462 

chloride, 463 
troches, 342 

citrate, 467 

iodide, 463 

nitrate, 464 

phosphate, 467 

salicylate, 467 

sesquicarbonate, 462 

sulphate, 468 

valerianate, 464 
Amorphous substances, 176 
Amyl alcohol, 574 

nitrite, 580 

valerianate, 618 
Amylin, 561 
Amyloid, 546 
Amylolysis, 649 
Amylopsin, 650 
Amylum, 564 
Analgesine, 556 
Anethol, 398, 600 
Anhydride, abietic, 606 

acetic, 590 

chromic, 512 

nitric, 417 

phosphoric, 417 

sulphuric, 417 

sulphurous, 417 
Anilids, 556 
Aniline, 555 
Animal ferments, 649 
Annidalin, 586 
Anodynine, 556 
Antifebrin, 556 
Antimonial powder, 363, 522 
Antimonii et potassii tartras, 522 

oxidum, 522 

sulphidum, 522 

purificatum, 522 

sulphuratum, 522 
Antimonium tartaratum, 523 
Antimonous oxide, 523 

sulphide, 524, 525 



INDEX 



657 



Antimony and potassium tartrate, 522 

compound pills, 331, 522 

oxide, 523 

pentasulphide, 525 

sulphide, 52-4 
puriried, 524 

sulphurated, 525 

trioxide, 523 

wine. 522 
Antipyrine, 556 
Apocodeine, 630 

Apomorphine hydrochloride, 625 
Apple oil, 618 
Aqua amnioniae, 207, 461 
fortior, 207, 461 

amygdalae aruarae, 207 

anisi, 20S 

aurantii riorum, 207 
fortior, 208 

camphora?, 208 

chlori, 207, 408 

chloroformi, 207 

cinnamomi, 208 

creosoti, 207 

destillata, 208 

foeniculi, 208 

hydrogenii dioxidi, 207, 405 

menthae piperita?, 208 
viridis, 208 

regia, 423 

rosae, 207 

fortior, 208 
Aquila alba, 516 
Apotheme, 267 

Approximate measurements, 43 
Arabin, 564. ~rio 
Arabinose, 565 
Argenti cyanidum, 533 

iodidum, 533 

nitras, 533 

dilutus, 533 
fusus, 533 
Argenti oxidum, 533 
ArgoL 432 
Aristol, 586 

Arrangement of the Pharmacopoeia, 18 
Arsenate sodium, solution, 522, 52S 
Arseni iodidum. 522 

Arsenic and mercuric iodide solution, 
527 

iodide, 525 

triiodide, 525 

trioxide. 526 

white, 526 
Arsenite, potassium; solution. 522. 52 x 
Arsenous acid, 526 

solution, 527 
Asaprol, 560 
Aselline, 589 
Asphalt, 555 
Asymmetric system, 181 
Atropine, 626 

sulphate, 627 



Auri et sodii chloridum, 533 
Auric chloride, anhvdrous, 542 



BALANCE, compound lever, 35 
hand, 33 

prescription, 34 

solution, new, 36 

the, 32 

torsion, 36 
Balsams, 186 
Barbaloin, 645, 646 
Barfoed's solution. 567 
Barii dioxidum, 469 
Barilla, 411 
Barium dioxide, 469 
Barthel's alcohol lamp, 72 
Basham's mixture, 505 
Bassorin, 565 
Bath, sand, 79 

steam, 79 

water, 80 

constant, 81 
Bay rum, 239 
Beechwood creosote, 553 

tar, 552 
Beeswax, 191,589 
Benne oil, 195 
Benzene, 545, 555 
Benzin, 555 
Benzoic aldehyde. 598 
Benzol, 555 
Benzonaphtol, 560 
Benzoyl chloride, 600 

eugenol, 600 

guaiacol. 554 
Berberine, 641 
Bergamiol. 598 
Beta-naphthol, 560 
Betol, 5 GO 

Bibron's antidote, 410 
Birch tar, 598 
Bismuth and ammonium citrate, 529 

citrate, 529 

oxide, 531 

salicylate, 531 

subcarbonate, 530 

subgallate, 531 

subiodide, 532 

subnitrate, 530 
Bismuthi citras. 522 

et ammonii citras, 522 

magisterium, 531 

subcarbona-. 522 

subnitras, 522 
Bitter principles. 645 
Black draught, 217 
Blancard's pills. 332 
Blaud's pills, 331 
Block weights, 38 
Blue vitriol, 533 
Bcettger's test, 567 
Boiler, steam, 78 
42 



658 



INDEX. 



Boiling-point, 82 
Boluses, 308 
Borax, 445 
Borneol, 603 
Boroglyceride. 231 
Boroglycerin, 231 
Boron^ 416 

trioxide, 419 
Bougie mould, 397 

Mitchell's, 397 
Bougies, 390 

gelatin, 396 
Brandy, 239, 240 
British gum, 563 
Bromal, 586 
Bromine, 409 
Bromoform, 583 
Bromol, 586 
Brown mixture, 307 
Bunsen burners, 74, 75 
Burner safety, 76 
Burners, gas, 73-76 
Burnett's disinfecting fluid, 541 
Butter of cacao, 195, 589 
Butyl chloral hydrate, 585 



pACHETS, Mohrstadt's, 359 
\J rice-flour, 360 
Cadinene,599, 601, 602. 603 
Caffeina citrata effervescens, 367, 368 
Caffeine, 627 

citrated, effervescent, 368 
Calabarine, 634 
Calcii bromidum, 469 

carbonas prsecipitatus, 469 

chloridum, 469 

hypophosphis, 469 

phosphas prsecjpitatus, 469 

sulphas exsiccatus 469 
Calcination, 158 
Calcined plaster, 473 
Calcium bromide, 470 

carbonate, 471 

carbonate, precipitated, 470 

chloride, 471 

hydroxide, 473 

hypophosphite, 471 

lactophosphate, syrup, 224, 469 

naphtalenesulphonate, 560 

naphtolsulphonate, 560 

oxide, 473 

phosphate, precipitated, 472 

sulphate, crystalline, 473 
dried, 473 
Calomel, 515 

hydrosublimed, 515 
Calx, 469 

chlorata, 469 

sulphurata, 469 
Camphene, 597 
Camphor, 604 

artificial 604 



Camphor, cubeb, 600 

monobromated, 605 
Cane-sugar, 568 
Capsulator, Viel's, 327 
Capsule-filler, Acme, 360 

Davenport's, 359 
Capsuling pill-masses, 326 
Caramel, 569 
Carbo-hydrogen oils, 202 
Carbolic acid, 555 557 
crude, 557 
synthetic, 557 
Carbon, 416 

disulphide, 416 
Carbonyl, 552 

chloride, 582 
Carboxyl, 607 
Carragheen, 565 
Carvacrol, 603 
Carvol, 599, 603 
Carvene, 597 
Caryophyllene, 599 
Castor oil, 194, 589 
Catechol, 549, 557 
Caustic, lunar, 544 
toughened, 544 
Celluloid, 548 
Cellulose, 546 

nitrates, 547 
Centrifugal separators, 151 
Cera alba, 191 
flava, 191 
Cerasin, 565 
Cerate camphor, 378 
cantharides, 378 
Goulard's, 378, 379 
lead subacetate, 378, 533 
resin, 378 
spermaceti, 378 
Turner's, 538 
Cerates, 378 
Ceratum, 378 

camphora?, 378 
cantharidis, 378 
cetacei. 378 

plumbi subacetatis, 378 
resinee, 378 
Ceresin. 596 
Cetraria 563 

decoction, 214 
Ceric sulphate, 484 
Cerii oxalas, 482 
Cerium nitrate, 485 

oxalate, 484 
Cerous sulphate, 484 
Cerussa, 535 
Cetaceum, 192 
Cevadine, 640 
Cevadilline, 640 
Chalk mixture, 305, 306, 469 
powder, compound, 363, 469 
precipitated, 470 
prepared, 471 



INDEX. 



659 



Chalk troches, 342, 469 
Charcoal, 549 

animal, 416 

wood, 416 
Chavicol, 602 

Chemical incompatibility, 297 
Chili saltpetre, 449 
Chloral, 583 

alcoholate, 584 

hydrate, 584 
butyl, 585 
croton, 585 

urethane, 584 
Chloralamide, 584 
Chloralimide, 584 
Chloride of lime, 474 
Chlorine, 408 

water, 408 
Chloroaurate of sodium, 541 
Chloroauric acid, 542 
Chloroform, 582 
Cholesterin, 589 

fats, 590 
Chrome alum, 482 
Chromic acid, 512 

anhydride, 512 

trioxide, 512 
Chrysarobin, 646 
Cinchonidine, 628 

salicylate. 641 

sulphate. 628 
Cinchonine, 628 

sulphate, 628 
Cinene, 597 

Cineol, 599. 600, 602, 603 
Cinnamic aldehyde, 599 
Citral. 600. 601 
Citrene, 597 
Citronellal, 600, 601 
Clarification, 147 
Classification of natural products used in 

pharmacy, 185 
Cleavage, 177 
Clinometric group, 177 
Clinorhombohedral system, 181 
Clinorhombic system, 181 
Coal tar, 555 

creosote, 558 
Coating for pills, 319 

balsam of tolu, 327 
collodion, 327 
gelatin, 321 
keratin, 328 
pearl, 328 
salol, 329 
silver, 319 
sugar, 320 
Cocaine. 629 

hydrochloride, 629 

synthetic, 629 
Cocamine, 629 
Codeine, 630 
Codex mediccraentarius. 17 



Cod-liver oil, 194, 589 

Cohobation, 210 

Colation, 132 

Collection and preservation of crude 

drugs, 91 
Collodion, cantharidal, 285 

flexible, 285 

plain, 284 

styptic, 285 
Collodions, 284 
Collodium, 284 

cantharidatum, 285 

flexile, 285 

stvpticum, 285 
Colloid, 152 
Colloxylin, 547 
Cologne spirit, 573 

Comparative table of metric and other 
fluid measures, 31 
weights, 30 
Compressed-tablet machines, 346, 347 

tablets, 344 

simple mould for, 346 
Condenser, all glass, 162 

Beindorf, 163 

Liebig, 161 

Mitscherlich, 164 

Squibb, 162 

worm, 163 
Confectio rosae, 335 

sennae, 335 
Confections, 335, 

official, 335 
Coniine, 641 
Contusion, 94 
Ccnvolvulin, 606 
Copperas, 489 
Copper acetate, 534 

alum, 534 

arsenite, 534 

nitrate, 534 

sulphate, 533 
Corn starch, 564 
Cornutine, 642 
Corrosive sublimate, 517 
Cotton, 546 

absorbent, 547 

benzoated, 547 

borated, 547 

carbolated. 547 

collodion, 547 

gun, 547 

iodized 547 

medicated, 547 

salicvlated. 547 
Cottonseed oil, 193, 589 
Cream of tartar, 432 
soluble, 433 
Creosol. 552 
Creosote, 553 

v beechwood, 553 

coal-tar, 553, ~h)S 

wood tar, ">^'-> 



660 



INDEX. 



Cresolal, 615 
Cresols, 553, 558 
Creta prseparata, 469 
Croton oil, 195 
Crude tartar, 432 
Crystallization, 176 

water, 183 
Crystalloid, 152 
Crystals, acicular, 177 

angles, 176 

axes, 176 

edges, 176 

faces, 176 

laminar, 177 

nursing, 184 

prismatic, 177 

tabular, 177 
Cubeb camphor, 600 
Cubic saltpetre, 449 

system, 177 
Cuminol, 600 
Cupri sulphas, 533 
Cuprum aluminatum, 534 
Curran water-still, 209 
Curtman's pipettes, 41 , 42 
Cutter for herbs and roots, 95 

vanilla, 99 
Cymene, 603 
Cymol, 605 



DAGGETT, 598 
Daturine, 626 
Dead oil, 557 
Decantation, 145 
Decoction, 116 

cetraria, 214 

sarsaparilla, compound, 214 
Decoctions, 213 

official, 214 
Decoloration, 149 
Decrepitation, water, 183 
Deliquescent crystals, 183 
Dermatol 531 
Desiccation, 157 
Desiccators, 158 
Dextrin, 546, 563 
Dextrose, 546, 563, 566 
Diachylon ointment, 373 

plaster, 595 
Dialysate, 153 
Dialyser, 152 
Dialysis, 151 
Diastase, 571 

Diethylsulphonyl-dimethylmethane, 
Diffusate, 153 
Diffusion, 152, 153 
Digestion, 116 
Diiodosalol, 615 
Dimethylketone, 552 
Dimethylphenylpyrazolon, 556 
Dimetric system, 178 
Dimorphous crystals, 176 



587 



Dipentene, 202, 597 
Disinfecting fluid, Burnett's, 541 
Disintegrator, Mead's, 95 
Dispensatories, 23 
Distillation, 159 

destructive, 174 

dry, 175 

fractional, 174 
Diterpenes, 597 
Donovan's solution, 211 
Doubly oblique prismatic svstem, 181 
Drug mills, 95-101 
Drying oils, 187 
Duboisine, 626 
Dulcitol, 566 



EARTH WAX, 596 
Eau de Javelle, 456 
Ecgonine, 629 

methyl, 629 

benzoyl, 629 
Ecuelle a piquer, 200 
Effervescent citrated caffeine, 368 

lithium citrate, 368 

magnesium citrate, 368 
sulphate, 368 

potassium citrate, 368 

salts, 366 
Efflorescence, 183 
Elseosacchara, 365 
Elaidin, 377, 592 
Elaterin, 646 

trituration, 365 
Electric plate stove, 71 
Elixir, aromatic, 234 

aromaticum, 234 

ferri, quininse et strychninae phos- 
phatum, 234 

pepsin, bismuth, and strychnine, 236 

pepsini, bismuthi et strychninse, 236 

phosphates of iron, quinine, and 
strychnine, 235 

phosphori, 234 

phosphorus, 234 

vitriol, 427 
Elixirs, 233 

official, 234 
Elutriation, 104 

Emplastrum ammoniaci cum hydrargyro, 
389, 513 

arnicse, 389 

belladonna?, 389 

cantharidis, 379 

capsici, 389 

ferri, 389 

hydrargyri, 389, 513 

ichthyocollas, 389 

opii, 389 

picis burgundicae, 389 

picis can thai idatum, 389 

plumbi, 389, 533 

resinse, 389 



INDEX. 



661 



Emplastrum saponis, 389 

vesicans, 379 
Empyreuma, 175 
Empyreuniatic oils, 204 
Emulsifier, Morton's, 293 
Emulsifying agents, 291, 292 
Emulsion, almond, 294 

ammoniac, 294 

asafetida, 294 

chloroform, 294 
Emulsions, 286 

continental method, 288 . 

double, 289 

English method, 288 

ether, 290 

gum resin, 287 

lycopodium, 287 

official, 293 

oil, 287 

seed, 287 

volatile oil, 290 
Emulsum ammoniaci, 294 

amygdalae, 294 

asafcetida?, 294 

chloroformi, 294 
Enfleurage, 201 
Enterprise press, 150 
Epsom salt, 480 
Ergotin, 273 
Ergotinine, 642 
Eserine, 634 

salicylate, 634 
Essence bitter almonds, 238 

lemon, 239 

nutmeg, 239 

peppermint, 239 

spearmint, 239 
Essences, 238 
Ethereal oil, 577 
Ether, 575 

acetic. 576 

hydrobromic, 583 

sulphuric, 575 

petroleum, 555 
Etherification, 575 
Ethyl acetate, 576 

aldehyde. 581 

alcohol, 571 

bromide, 583 

nitrite, 577, 578 

sulphate, 577 
Eucalvptol, 599, 600, 602 
Eugeiiol, 599. 602, 603 
Euphorine, 586 
Europhen, 586 
Evaporation, 154 
Everitt's salt, 609 
Exalgine, 556 

Excipients for pill-masses, 311 
Expressed oil of almond, 192 
Exsiccation, 157, 158 
Extract aconite, 270, 272 

aloes, 270, 272 



Extract arnica root, 270 

belladonna leaves, 270, 272 

cimicifuga, 270 

cinchona, 270, 272 

colchicum root, 270, 272 

colocynth, 270, 273 

compound, 270, 273 

conium, 270, 273 

digitalis, 270 

ergot, 270, 273 

euonymus, 270 

gentian, 270, 274 

glycyrrhiza, 270, 274 

ha?matoxylon, 270, 274 

hyoscyamus, 270, 275 

Indian cannabis, 270, 272 

iris, 270 

jalap, 270, 275 

juglans, 270 

krameria, 270, 275 

leptandra, 270 

nux vomica, 270, 275 

opium, 270, 276 

quassia, 270, 277 

podophyllum, 270 

physostigma, 270 

rhubarb, 270, 277 

stramonium seed, 270, 277 

taraxacum, 270, 277 

uva ursi, 270, 277 
Extraction, 116 
Extracts, 265 

alcoholic, 268 

aqueous, 267 

British, 265 

changes, by evaporation, 266 

consistence of, 266 

fluid, 255 

official, 259 

hydro-alcoholic, 268 

official, 270 

powdered, 269 
Extractum aconiti, 271, 272 

aloes, 271, 272 

arnica?, 271 

belladonna?, 272 

foliorum alcoholicum, 271, 272 

cannabis Indiae, 271, 272 

castanea? fluidum, 261 

cimicifugse, 271 

cinchona?, 271, 272 

colchici radicis, 271, 272 

colocynthidis, 271, 273 
compositum, 271, 273 

conii, 271, 273 

cubebarum. 280 

digitalis, 271 

ergota?, 271, 273 

euonymi, 271 

ferri pomatum, 508 

filicis, sethereum, 280 

gentianae, 271, 274 

glycyrrhiza? fluidum, 261 



662 



INDEX. 



Extractum glycyrrhizse purum, 271, 274 
hsematoxyfi, 271, 274 
hyoscyami, 271, 275 
iridis, 271 
jalapa?, 271, 275 
juglandis, 271 
krameria?, 271, 275 
leptandrae, 271 
lupulini fluidum, 262 
nucis vomica?, 271, 275 

fluidum, 262 
opii, 271, 276 
physostigmatis, 271 
podophylli, 271 
pruni virginiana? fluidum, 262 
quassia?, 271, 277 
rhamni purshiana? fluidum, 262 
rhei, 271, 277 

fluidum, 263 
sangumariae fluidum, 263 
sarsaparillae fluidum, 263 
scillae fluidum, 263 
Scutellariae fluidum, 263 
senega? fluidum, 263 
stillingia? fluidum, 262 
stramonii seminis, 271, 277 
taraxaci, 271, 277 
tritici fluidum, 264 
uva? ursi, 271, 277 

fluidum, 264 
veratri viridis fluidum, 264 



FAEINOSE, 561 
Fats and fixed oils, 186 
rancidity of, 187 
Fehling's solution, 567 
Fel bovis purificatum, 270 
Fenchone, 600 
Ferments, animal, 649 
Ferric acetate solution, 502 
albuminate solution, 509 
ammonium sulphate, 493 
benzoate, 507 
chloride, 494 

solution, 503 
tincture, 506 
citrate, 495 

soluble, 499 
solution, 503 
wine of, 253, 487 
ferrocyanide, 508 
hydrate, 496 
hydroxide, 496 

with magnesia, 496 
hypophosphite, 497 
nitrate solution, 504 
oxyhydrate, 496, 510 
phosphate, soluble 497 
pyrophosphate, soluble, 498 
subsulphate solution, 504 
sulphate solution, 505 
valerianate, 499 



Ferri carbonas saccharatus, 486 
chloridum, 486 
citras, 486 

et ammonii citras, 487 
sulphas, 486 
tartras, 487 
et potassii tartras, 487 
et quinina? citras, 487 
solubilis, 487 
et strychnina? citras, 487 
hypophosphis, 487 
iodidum saccharatum, 486 
laetas, 486 
oxidum hydratum, 487 

cum magnesia, 487 
phosphas solubilis, 487 
pyrophosphas solubilis, 487 
sulphas, 486 

exsiccatus, 486 
granulatus, 486 
valerianas, 487 
Ferrous bromide, 507 
carbonate mass, 490 
pills, 331 
saccharated, 490 
iodide, 508 
pills, 332 
saccharated, 491 
syrup, 224, 492 
lactate, 491 
malate, impure, 508 
oxalate, 508 
salicylate, 509 
sulphate, 489 
dried, 489 
granulated, 489 
Ferrum, 486 

reductum, 486 
tartaratum, 500 
Ferryl, 500 
Filter-bag, 133 
Filtering-media, 132, 144 
Filter, oil, Warner's, 134 
plain, 135 

Classen's, 136 
plaited, 137 
Filter-pumps, 142 
Filtration, 132 

of volatile liquids, 140 
Florentine flasks, 199 
Flowers of sulphur, 414 

of zinc, 539 
Fluid extract aconite, 259 
apocynum, 259 
arnica root, 259 
aromatic powder, 259 
asclepias, 259 
aspidosperma, 259 
belladonna root, 259 
bitter orange peel, 259 
buchu, 259 
calamus, 259 
calumba, 259 



INDEX. 



663 



Fluid extract cannabis Indica, 259 
capsicum. 259 
cascara, tasteless, 262 
castanea, 259, 261 
chimaphila, 259 
chirata, 259 
cirnicifuga, 259 
cinchona, 259 
coca, 259 
colchicum root, 259 

seed, 259 
conium, 259 
convallaria, 259 
cotton-root bark, 259 
cubeb, 259 
cypripedium, 259 
digitalis, 259 
dulcamara, 259 
ergot. 260 
eriodictyon, 260 
eucalyptus, 260 
eupatorium, 260 
frangula, 260 
gelsemium, 260 
gentian, 260 
geranium, 260 
ginger, 260 
glycyrrhiza, 260, 261 
grindelia, 260 
guarana, 260 
hamamelis, 260 
hydrastis, 260 
hyoscyamus, 260 
ipecac, 260 
iris, 260 
kousso, 260 
krameria, 260 
lappa, 260 
leptandra, 260 
lobelia, 260 
lupulin, 260, 262 
matico, 260 
menispermum, 260 
mezereum, 260 
nux vomica, 260, 262 
pareira, 260 
Phytolacca root, 260 
pilocarpus, 260 
podophyllum, 260 
quassia, 260 

rhamnus purshiana, 260, 262 
rhubarb, 260, 263 
rhus glabra, 260 
rose, 260 
rubus, 260 
rumex, 260 
sanguinaria, 260, 263 
sarsaparilla, 260, 263 

compound, 261 
savin, 261 
scoparius, 261 
Scutellaria, 261, 263 
senega, 261, 263 



Fluid extract senna, 2(51 

serpentaria, 261 

spigelia, 261 

squill, 261, 263 

stillingia, 261, 263 

stramonium seed, 261 

taraxacum, 261 

triticum, 261, 264 

uva ursi, 261, 264 

valerian, 261 

veratrum viride, 261, 264 

viburnum opulus, 261 
prunifolium, 261 

wild cherry, 261, 262 

xanthoxylum, 261 
Fluid extracts, 255 

history, 255 

official, 259 

preparation, 257 
Formyl terchloride, 583 
Fowler's solution, 212, 528 
Fractional condensation, 174 

distillation, 174 
Fructose, 567 
Fruit sugar, 566 
Funnels, 139 
hot-air, 141 
hot- water, 141 
Furfurol, 549 

GALACTOSE. 565 
Gallacetophenone, 612 
Gallactophenone, 612 
Gas burners, 73-76 

stoves, 77 
Gelatin-coater for pills, Colton's, 325 
Franciscus', 323 
Maynard's, 324 
Patch's, 322 
porcupine, 322 
Gelatin-coaxing, 321 
Geraniol, 600, 601, 603 
Glasses, medicine, graduated, 44 
Glauber's salt, 453 
Glonoin, 595 

spirit, 595 
Glucose, 563, 566 
Glucoses, 566 
Glucosides, 645 
Gluten, 564, 566 
| Glycerin, 195, 588,^ 595 
suppositories, 398 
Glycerite, carbolic acid, 230 

bismuth and sodium tartrate, 237 
boroglycerin, 231 
hydrastis, 231 
starch, 231 
tannic acid, 230 
yelk of egg, 232 
Glycerites, 230 

Glyceritum acidi carbolici, 230 
tannici, 230 



664 



INDEX. 



Glyceritum amyli, 230 

boroglycerini, 230 

hydrastis, 280 

vitelli, 232 
Glyceryl, 588 

borate, 231 

hydroxide, 588, 595 

trinitrate, 595 
Glycyrrhizin, 646 

ammoniated, 646 
Gold and sodium chloride, 541 

chloride, 542 
Golden sulphur of antimony, 525 
Gossypium, 546 
Goulard's extract, 537 
Graduates, Acme, 41 

conical, 40 

cylindrical, 40 

Phenix, 40 

tumbler-shaped, 40 
Granulation, 106 
Granular effervescent salts, 366 
Granules, 308 
Granulose, 562 
Grape-sugar, 566 
Gray powder, 514 
Grommets, 156 
Guaiac, 606 
Guaiacol, 552, 554 
Gum-resins, 186 
Gums, true, 185, 561, 564 
Gun-cotton, 547 
Gypsum, 473 

dried, 473 



HEAT, 70 
amount, 71 

control, 79 

intensity, 71 

measurement, 87 

of fluidity, latent, 84 

regulation, 77 

sources, 71 
Heavy oil, 559 

of wine, 577 
Hemihedral, 177 
Hesperidine, 597 
Hexagonal system, 180 
Hoffmann's anodyne, 238, 239 
Holohedral, 177 
Honey, 567 

adulterations, 568 

clarified, 230 

of rose, 230 
Honeys, 230 
Hubl's iodine test, 591 
Hydrargyri chloridum corrosivum, 513 
mite, 513 

cyanidum, 513 

iodidum fiavum, 513 
rubrum, 513 

oxidum fiavum, 513 



Hydrargyri oxidum rubrum, 513 

subsulphas flavus, 513 
Hydrargyrum amidato bichloratum, 515 

ammoniatum, 513 

cum creta, 513 
Hydrastin, 642 
Hydrastine, 630, 642 
Hydrastinine hydrochloride, 630 
Hydriodic acid, 412 

syrup, 223, 412 
Hydrocarbons, 545' 
Hydrogen, 405 

dioxide, 405 

solution, 406 

phosphide, 471 
Hydroquinol, 557 
Hydroquinone, 557 
Hydronaphtol, 560 
Hydrous wool-fat, 191 
Hygrine, 629 
Hygroscopic, 183 
Hyoscine hydrobromide, 631 
Hyoscy amine hydrobromide, 631 

sulphate, 631 
Hypnal, 584 
Hypodermic tablets, 353 



TNCINERATION, 158 

1 Incompatibilities, summary of, 303 

Incompatibility, chemical, 297 

pharmaceutical, 296 

therapeutical, 302 
Infusion, 116 

pot, Squire's, 215 
Infusions, 215 

official, 216 
Infusum cinchona?, 216 

digitalis, 216 

pruni virginianse, 216 

senna? compositum, 217 
Inorganic acids, 417 

substances, 403 
Interstitial water, 183 
Inulin. 563 
Inverted sugar, 567 
Iodine, 411 

caustic, Churchill's, 412 

ointment, 412 

solution (Lugol's), 211, 412 

tincture, 412 

Churchill's, 412 
decolorized, 412 
Iodoform, 585 
Iron, 487 

albuminate, 507 
solution, 509 

alum, 482 

and ammonium acetate solution, 505 
citrate, 499 
tartrate, 500 
potassium tartrate, 500 
quinine citrate, 501 



INDEX. 



QG5 



Iron and quinine citrate, soluble, 
502 

and strychnine citrate, 502 

arsenate, 507 
syrup, 510 

benzoate, 507 

bitter wine of, 253, 487 

bromide, 507 

citro-chloride, tincture, 510 

citro-iodide, syrup, 510 

dialyzed, 507 ' 

ferrocyanide, 508 

iodide, 508 
pills, 332 
syrup, tasteless, 510 

malate, 508 

mixture, compound, 306, 493 

oxalate, 508 

oxide saccharated, 509 
soluble, 509 
syrup, 510 

peptonate, 509 

persulphate solution, 505 

phosphate, 508 

plaster, 387, 487 

reduced, 487 

salicylate, 509 

subcarbonate, 509 

tincture, tasteless, 510 

troches, 342, 487 
Isocholesterin, 589 
Isomorphous substances, 177 
Isopropylcocaine, 029 



TABOKINE, 634 
J Jalap extract, 270, 271, 275 

resin, 281, 606 
Javelle water, 456 
Jervine, 640 



KENTISH liniment, 382 
Keratin, 328 
coating, 328 
Keratinized pills, 328 
Kermes mineral, 525 
Kerner's test, 637 
Ketones, 552 
Koettstorfer's saponification factor, 189, 

591 
Konseal filling and closing apparatus, 

360 
Konseals, 359 
Koppeschaar's solution, 558 



LABARRAQUE'S solution, 455 
Lactose, 568, 569 
Lactucerin, 248 
Lactucic acid, 248 
Lactucin, 248 
Lactucopicrin, 248 



Lard, 190, 588 

oil, 192, 588 
Lana philosophica, 539 
Lanolin, 191, 589 
Lapis divinus, 534 
Lead acetate, 534 

carbonate, 535 

ointment, 376, 533 

iodide, 535 

ointment, 376, 533 

nitrate, 535 

oxide, 536 

plaster, 388, 389, 533 

subacetate cerate, 378, 533 
solution, 536 

sugar, 535 

white, 535 
Leeching, 116 
Leucomaines, 619 
Levigation, 104 
Levulosan, 569 
Levulose, 563, 567 
Lichenin, 563 
Lignin, 545, 546 
Lignose, 545 
Lime, 473 

caustic, 473 

chlorinated, 473 

liniment, 380, 469 

milk, 471, 473 

solution, 475 

saccharated, 476 

sulphurated, 474 

syrup, 224, 475 

unslaked, 473 

water, 475 
Limonene, 202, 597 
Linalool, 598, 600, 601 
Linaloyl acetate, 598, 601 
Liniment, ammonia, 380, 381 
camphorated, 381 

belladonna, 380 

camphor, 380 

chloroform, 380, 381 
compound, 381 

compound mustard, 381 

kentish, 382 

lime, 380, 469 

soap, 381 

soft soap, 381 

turpentine, 382 

volatile, 381 
Liniments, 380 
Linimentum ammonia;, 380, 461 

belladonnae, 380 

calcis, 380, 469 

camphor?e, 380 

chloroformi, 380 

saponis, 381 
mollis, 381 

sinapis compositum, 381 
' terebinthinse, 381 
Linolein, 588, 589 



666 



INDEX. 



Linoxin, 590 

Linseed oil, 193, 589 

Lint, patent, 546 

Liquor acidi arsenosi, 211, 522, 527 

ammonii acetatis, 212, 461, 466 
arsenicalis, 528 
arseni et hydrargyri iodidi, 211, 522, 

527 
calcis, 211, 469,475 
ferri acetatis, 212, 487, 502 
chloridi, 212, 487, 503 
citratis, 212, 487, 503 
et ammonii acetatis, 212, 487 , 505 
nitratis, 212, 487, 504 
subsulphatis, 212, 487, 504 
tersulphatis, 212, 487, 505 
hydrargyri nitratis, 212, 513, 520 
iodi compositus, 211 
magnesii citratis, 212, 478, 480 
natrii caustici, 455 
plumbi subacetatis, 212, 533, 536 

dilutus, 211 
potassse, 211, 212, 429, 439 
potassii arsenitis, 212, 429, 522, 528 

citratis, 212, 429, 440 
sodse, 211, 212, 442. 455 

chlorate, 212, 442. 455 
sodii arsenatis, 211, 442, 522, 528 

silicatis, 212, 442, 456 
zinci chloridi, 212, 533, 540 
Litharge, 536 
Lithii benzoas, 458 
bromidum, 458 
arbonas, 458 
citras, 458 

effervescens, 458 
Lithium benzoate, 458 
bromide, 458 
carbonate, 459 
citrate, 459 

effervescent, 460 
salicylate, 460 
Liver of sulphur, 430 
Lixiviation, 116 
Lozenge apparatus, 340 
board, Harrison's, 338 

Procter's, 338 
cutters, 339 
punches, 339 
Lozenges, 336 

ammonium chloride, 342 

catechu, 342 

chalk, 342 

cubeb, 342 

cutting, 337, 340 

drying, 341 

gelatin, 341 

ginger, 343 

glycyrrhiza and opium, 342 

ipecac, 342 

iron, 342 

krameria, 342 

morphine and ipecac, 342 



Lozenges, official, 342 

peppermint, 342 

potassium chlorate, 343 

santonin, 343 

sodium bicarbonate, 343 

tannic acid, 342 

Lugol's solution, 211, 412 
Lysimeter, Kice's, 111 



MACERATION, 116 
Magendie's solution, 633 
Magma, 106 . 
Magnesia, 478 

alba, 479 

calcined, 478 

carbonas, 478 479 

citras effervescens, 478, 480 

heavy, 478 

light, 478 

ponderosa, 478 

sulphas, 478, 480 
Magnesium carbonate, 479 

citrate, effervescent, 368, 4 80 
solution, 480 

sulphate, 480 

effervescent, 368, 480 
Maltose, 563, 568, 570 
Malt-sugar, 568, 570 
Manganese dioxide, 511 

sulphate, 512 
Mangani dioxidum, 511 

sulphas, 511 
Manganous sulphate, 512 
Mannitol, 566 
Marsh-gas, 549 
Massa copaibse, 333 

ferri carbonatis, 333, 486 

hydrargyri, 333, 513 
Mass, blue, 334 

copaiba, 333 

ferrous carbonate, 334, 486, 490 

mercury, 334, 513 

Vallet's. 334 
Mayer's solution, 622 
Mead's disintegrator, 95 
Measure, fluid, 26 

imperial, 26 

standards, 26 

symbols, 26 

United States, 26 

units, 26 
Measurements, approximate, 43 
Measures, domestic, 43 

graduate, 40, 41 
Mechanical subdivision of drugs, 94 

shaker, 514 
Medicine glasses, 44 
Mel despumatum, 230 

rosse, 230 
Melt, 437 
Menstrua, 115 
Menthol, 602, 605 



INDEX. 



667 



Menthone, 602, 605 

Mercaptol, 587 

Mercurial ointment, 376, 513 

plaster, 386, 513 
Mercuric carbolate, 520 

chloride, corrosive, 517 

cyanide, 517 

diphenate, 520 

iodide, red, 518 

nitrate ointment, 377, 513 
solution, 520 

oleate, 382, 384, 513 

oxalate, 519 

oxide, red, 519 

ointment, 376, 513 

oxide, yellow, 518 

ointment, 376, 513 

phenate, 520 

salicylate, 521 

subsulphate, yellow, 519 

sulphate, 520 
Mercurius dulcis, 516 
Mercurous chloride, mild, 515 

iodide, yellow, 516 

tannate, 520 
Mercury, 513 

acid nitrate, 520 

amido-chloride, 515 

ammoniated, 515 

ointment, 376, 513 

with chalk, 514 
Metadioxybenzene, 557 
Methane, 545 
Methozine, 556 
Methvl acetanilid, 556 

alcohol, 549, 552 

catechol, 554 

morphine, 630 
. salicylate, 598 600 604 

theobromine, 627 
Methylated spirit, 452 
Metric measure, abbreviations in U. S. 
Pharmacopoeia, 26 
standards, 32 
tables, 

system, 27 
Metrologv, 24 
Milk-sugar, 568, 569 
Mills, 96, 97, 98,100, 101 
Mindererus, spirit of, 212,466 
Mineral wax, 596 
Minim pipettes, 41 , 42 
Mistura cretse, 305, 306, 469 

ferri composita, 305, 306 ; 486 
et ammonii acetatis, 506 

glycyrrhizse composita, 306 

potassii citratis, 212, 441 

rhei et sodse, 306, 307 
Mixer and sifter, 103 
Mixture, Basham's, 212, 505 

neutral, 441 
Mixtures, 295 



Mixtures, official, 305 
Molasses, 568 

Monobromated camphor, 605 
Monoclinic system, 181 
Monometric system, 177 
Monosodium arsenate, 444 
Monosymmetric system, 181 
Monsel's solution, 505 
Moore's test, 567 
Morphine 631 

acetate. 632 

hydrochloride, 633 

meconate, 643 

sulphate, 633 
Morrhine, 589 
Morrhuol, 589 
Mortar and pestle, 94, 104 
Moss's mechanical stirrer, 156 
Moss-starch. 563 
Mother-liquor, 183 
Mucilage acacia, 229 

elm, 229 

sassafras pith, 229 

tragacanth, 229 
Mucilages, 186, 229 
Mucilago acacise, 229 

sassafras medulla?, 229 

tragacanthse, 229 

ulmi, 229 
Mycose, 568 
Myrcene, 602 
Myristicin, 602 
Myristicol, 602 



NAPHTALENE, 555, 559 
crude, 559 

white, 559 
Naphtalin, 556 
Naphtalol, 560 
Naphtol, 560 

alpha, 560 

benzoate 560 

beta, 560 

salicylate, 560 
Naphtosalol, 560 
Narcotine, 643 
Nataloin, 645, 646 
Nerolol, 602 
Nerolyl acetate, 602 
Neutral principles, 645 
Nihil album, 539 
Nitre, 438 

cubic, 449 
Nitrobenzene, 555 
Nitrocellulose, 548 
Nitrogenated oils, 203 
Nitroglycerin, 595 
Non-crystallizable sugar, 56S 
Non-drying oils, 187 
Nursing ciystals, 184 



66S 



INDEX. 



OBLIQUE prismatic system, 181 
Octahedral system, 177 
Official cerates, 378 

confections, 335 

decoctions, 214 

definition, 21 

description, 23 

effervescent salts, 367 

elixirs, 234 

emulsions, 293 

extracts, 270 

fats and fixed oils, 190 

fluid extracts, 259 

glycerites, 230 

honeys, 230 

infusions, 216 

liniments 380 

lozenges, 342 

masses, 333 

mixtures, 305 

mucilages, 229 

name, 19 

ointments, 373, 376 

oleates, 384 

oleoresins, 280 

pills, 329 

plasters, 389 

powders, 363 

resins, 281 

solutions or liquors, 211 

spirits, 238 

syrups, 220 

tinctures, 243 

vinegars, 254 

waters, 206 

wines, 253 
Oil, almond, expressed, 192, 589 

apple, 618 

benne, 195 

black pepper, 281 

-cake, 188 

castor, 194, 589 

cod-liver, 194, 589 

cottonseed, 193, 589 

croton. 195, 589 

ethereal, 577 

lard, 192, 588 

linseed, 193, 589 

olive, 194, 589 

phosphorated, 415 

sesame, 194, 589 

sugars, 365 

teel, 195 
Oil of allspice, 603 

of anise, 598 

of bay, 602 

of bergamot, 598 

of betula, 598 

of birch, 598 

empyreumatic, 598 

of bitter almond, 203, 598 
synthetic, 203, 598 

of cade, 204, 599 



Oil of cajuput, 599 
of camphor, 604 
of caraway, 599 
of cassia, 599 
of chenopodium, 599 
of cinnamon, 599 
of cloves, 599 
of copaiba, 600 
of coriander, 600 
of cubeb, 600 
of erigeron, 600 
of eucalyptus, 600 
of fennel, 600 
of fieabane, 600 
of gaultheria, 600 
of hedeoma, 601 
of juniper, 601 

empyreumatic, 599 
of lavender flowers, 601 
of lemon, 601 
of mustard, volatile, 601 

synthetic, 601 
of myrcia, 602 
of neroli, 602 
of nutmeg. 602 
of orange flowers, 602 

peel, 602 
of pennyroyal, 601 
of peppermint. 602 
of pimenta, 603 
of rose, 603 
of rosemary, 603 
of santal, 603 
of sassafras, 603 

artificial, 603 
of savin, 603 
of spearmint, 603 
of sweet birch, 598 
of tar, 204, 603 
of theobroma, 195, 589 
of thyme, 603 
of turpentine, 604 

rectified, 604 
of wine, heavy, 577 
of wintergreen, 601 

artificial, 604 

synthetic, 604 
of wormwood, 599 
Oils, carbo-hydrogen, 202 
drying, 189 
empyreumatic, 204 
expressed, 188 
fixed, 186 
nitrogenated, 203 
non drying, 187 
oxygenated, 202 
sulphuretted, 203 
volatile. 196, 597 
Ointment, 373 

belladonna, 376 
carbolic acid, 376 
chrysarobin, 376 
diachylon, 373 



INDEX. 



669 



Ointment, Hebra's, 377 

iodine, 376 

iodoform, 376 

lead carbonate, 376, 533 
iodide, 376, 533 

mercurial, 376 

ammoniated, 376 

mercuric nitrate, 377 

nutgall, 376 

potassium iodide, 376 

red mercuric oxide, 376 

rose water, 373 

stramonium, 376 

sulphur, 376 

tannic acid, 376 

tar, 373 

veratrine, 376 

yellow mercuric oxide, 376 

zinc oxide, 376, 533 
Ointments, 370, 371 

preparation by chemical action, 
by fusion, 372 
by incorporation, 373 
Oleate, mercuric, 384 

potassium I solution), 383 

sodium (solution), 383 

veratrine, 384 

zinc, 384, 533 

powdered, 384 
Oleates, 382 

normal. 382 

ointments of, 384 
Olein, 190. 58S, 589 
Oleite, 371, 592 
Oleosacchara. 365 
Oleoresin aspidium. 280 

capsicum, 280 

cubeb, 280 

ginger, 281 

lupulin, 2S0 

male fern, 280 

pepper, 281 
Oleoresina aspidii, 280 

filicis, 280 

capsici, 280 

cubeba?, 280 

lupulini, 280 

piperis, 281 

zingiberis, 281 
Oleoresins, 186, 278 

official, 280 
Oleum adipis, 192 

amygdahe expressum, 192 

betulinum, 598 

filicis maris. 280 

gossipii seminis, 193 

jecoris aselli, 194 

lini, 193 

morrhuee, 194 

muscoviticum. 598 

olivse, 194 

phosphoratum, 415 

ricini. 194 



Oleum rusci, 598 

sesami, 195 

theobromatis, 195 

tiglii, 195 
Oriole tablet-compressor, 2>A~> 
Orthodioxy benzene, 5-57 
Orthometric group, 177 
Oxide, antimony, 523 

bismuth, 531 

lead, 536 

mercury, red, 519 
yellow, 518 

zinc, 539 
Oxylinolein, 590 
Ozokerite, 596 



DALMITIN, 588 

I Pancreatin, 650 
Paper pulp for filtering, 144 
376 Parabin, 565 

Para-acetphenetidin, 559 
Paraffin, 596 

oils, 596 
Paraldehyde, 581 
Parody ne, 556 
Pearl coating of pills, 328 
Pearls, apiol, 327 

chloroform, 327 

ether, 327 
Pectase, 565 
Pectin, 565 
Pectose, 56o 
Pectosic acid, 565 
Pepsin, 651 

saccharated, 654 
Pepsinogen, 651 

Percentage adjustment in liquids, 65, 66 
in solids, 67, 68 

solutions, 114 
Percolating-stand, 130 
Percolation, 117 

continuous, 131 
Percolator, copper, 123 

Dursse, 122 

for volatile liquids, glass, 121 
tin. 122 

glass, 119,120 

Oldberg, 119 

pressure, Count Keal. 124 

tin. covered. 120 

well-tube. Squibb, 123 
Percolators, 118 

pressure. 124 
Petroleum benzin, 596 

ether, 555, 596 

products, 595 
Petrolatum, 595 

hard, 595 

liquid, 595 

soft, 595 
Pharmaceutical incompatibility. 296 
Pharmacopoeias, 17 



670 



INDEX. 



Pharmacopoeias, history, 17 
Pharmacopoeia, United States, 18 
arrangement, 18 
plan, 18 
Phellandrene, 202, 597, 602 
Phenacetin, 559 
Phenazone, 556 
Phenol, pure, 557 
Phenols, 558 
Phenylamine, 556 
Phenylacetamide, 556 
Phenyl salicylate, 614 
Philosophers' wool, 539 
Phosphine, 471 
Phosphorated oil, 415 
Phosphorus, 415 
Physetolein, 588, 589 
Physostigmine, 633 
salicylate, 633 
sulphate, 634 
Picro toxin, 647 
Pill-coating, 319 

-compressor, Smedley, 346 

-dusting, 318 

-finisher, hard-wood, 318 

-machine, 317 

-masses, division, 316 

machines for mixing, 310 
-mortars, 309 
-roller, 317 
-tile, 317 
Pills, 308 

aloes, 329 

aloes and asafetida, 329, 330 
and iron, 329 
and mastic, 329 
and myrrh, 329 
alterative, Plummer's, 331 
antimony (compound 1 , 330, 331, 
asafetida, 330 
Blancard's, 332 
Blauds, 331 

carbonate of iron, 330, 331 
cathartic compound, 330, 331 

vegetable, 330 
ferrous carbonate, 331 

iodide, 330, 332 
Lady Webster dinner, 331 
official, 329 
opium, 330 
phosphorus, 330, 332 
Plummer's, 331 
rhubarb, 330 

compound, 330, 333 
Pilocarpine, 634 

hydrochloride, 634 
nitrate, 643 
Pilocarpidine, 634 
Pilulse aloes, 329 

et asafoetidse, 329 
et ferri, 329 
et mastiches, 329 
et myrrh se, 329 



522 



Pilulse, antimonii compositae, 330, 331, 
522 # 

asafcetidae, 330 

catharticae compositse, 330 
vegetabiles, 330 
• ferri carbonatis, 330, 331, 486 
iodidi, 330, 332, 486 
opii, 330 

phosphori, 330, 332 
rhei, 330 

composite, 330, 333 
Pinene, 202, 597, 600, 601, 602, 603, 604 
Piperoid, 281 
Pipettes, 42 
Pitch, 555 

black, 553 

liquid, 553 
Pix liquida, 553 
Plasma, 371, 563 

glycerini, 371 
Plaster, adhesive, 389 

ammoniac, with mercury, 389, 513 

arnica, 389 

belladonna, 389 

Burgundy pitch, 389 

capsicum, 389 

court, 389 

diachylon, 595 

fly, 388 

iron, 389 

isinglass, 389 

lead, 389, 533 

-masses, 389 

mercurial, 389 

opium, 389 

pitch, cantharidal, 389 

resin, 389 

roller, 387 

soap, 389 

warming, 389 
Plasters, 385 

breast, 387 

mammary, 387 

porous, 388 

spreading, 387 
Plumbi acetas, 533 

carbonas, 533 

iodidum, 533 

nitras, 533 

oxidum, 533 
Podophyllin, 282 
Podophyllotoxin, 606 
Podophyllum resin, 282 
Polymorphous, 177 
Polysolve, 371, 592 
Polyterpenes, 597 
Potash, caustic, 429 

red prussiate, 437 

yellow prussiate, 437 
Potassa, 429 

cum calce, 429 

solution, 439 

sulphurata, 429 



INDEX. 



671 



Potassa, sulphurated, 430 

with lime, 429 
Potassii acetas, 429 

bicarbonas, 429 

bichromas, 429 

bitartras, 429 

bromidum, 429 

carbonas, 429 

chloras, 429 

citras, 429 

effervescens, 429 

cyanidum, 429 M 

et sodii tartras, 429 

ferrocyanidum, 429 

hypophosphitum, 429 

iodidum, 429 

nitras, 429 

permanganas, 429 

sulphas, 429 
Potassium acetate, 431 

alum, 482 

and sodium tartrate, 436 
borotartrate, 433 

arsenite solution, 440, 513, 528 

benzenesulphonate, 558 

benzoate, 441 

bicarbonate, 431 

bichromate, 432 

bitartrate, 432 

bromide, 433 

carbonate, 434 

chlorate, 435 
troches, 343 

chloride, 441 

citrate, 435 

effervescent 435 
solution, 440 

cyanate, 436 

cyanide, 436 

dichromate, 432 

ferricyanide, 437 

ferrocyanide, 437 

hypophosphite, 437 

iodate, 438 

iodide, 438 

manganate, 438 

nitrate, 438 

permanganate, 438 
. salicylate, 441 

sulphate, 439 

sulphite, 441 

tartrate, 441 
Potio Riveri, 456 
Powder, antimonial, 363, 522 

aromatic, 363 

chalk, compound, 363 

-divider, Michael's, 356 

Dover's, 363, 364 

effervescent, compound, 564 

glycyrrhiza, compound, 363, 364 

gray, 514 

ipecac and opium, 364 

jalap, compound, 364 



Powder, James, 363 

liquorice, compound, 363, 364 
morphine, compound, 363, 364 
rhubarb, compound, 363, 364 
Seidlitz, 363 
Tully's, 363, 364 

Powders, 354 

in capsules, 358 
wafers, 359 
preparation of mixed, 355 

Practical pharmacy, 205 

Precipitant, 105 

Precipitate, 105 

Precipitation, 105 

Prentiss alcohol-reclaimer, 1 67 

Press, enterprise, 150 
tincture, 149 

Pricking-basin, 200 

Prollius' fluid. 621 

Proof-spirit, 574 

Propane, 588 

Propenyl, 588 
alcohol, 588 
trinitrate, 595 

Proteolysis, 649 

Ptomaines, 619 

Ptyalin, 649 

Pulegone, 601 

Pulvis antimonialis, 364, 522 
aromaticus, 364 
cretae compositus, 364, 469 
effervescens compositus, 363, 364 
glycyrrhizpe compositus. 363, 364 
ipecacuanhas et opii, 363, 364 
jalapee compositus, 363, 364 
morphinse compositus, 363, 364 
rhei compositus, 363, 364 

Pycnometers, 46 

Pyridine, 619 

Pyroacetic spirit, 552 

Pyrocatechin, 549, 557 

Pyrogallol, 611 

Pyroligneous acid, 549. 

Pyrolusite, 511 

Pyroxylic spirit, 552 

Pyroxylin, 547 



QUADRATIC system, 17: 
Quinidine 635 
sulphate, 635 
Quinine, 635 

bisulphate, 636 
bromide, 636 
disulphate, 637 
hydrobromide 636 
hydrochloride, 637 
muriate, 637 
salicylate, 643 
sulphate, 637 
tannate, 643 
v valerianate, 638 
Quinoline, 619 



672 



INDEX. 



REAGENT, Dragendorff's, 621 
Marine's, 621 

Mayer's, 621 

Scheibler's, 621 

Sonnenschein's, 621 
Reagents, alkaloidal, 621 
Receiver for volatile oils, 199, 200 
Receiving-jars, glass, 128 
Redistillation, 210 
Red precipitate, 519 

prussiate of potash, 437 
Reduction, 106 

Regular system of crystallization, 177 
Resina jalapse, 281 

podophylli, 281 

scaminonii, 281 
Resin jalap, 281, 606 

podophyllum, 282, 606 

scammony, 282, 606 
Resinol, 606 
Resinotannols, 606 
Resins, 185, 281 

official, 281 
Repercolation, 130 
Resorcin, 556 
Rhodinol, 603 
Resorcinol, 557 
Rhombic system, 179 
Rhombohedral system, 180 
Rice's lysimeter, 111 

still, 170 
Ricinolein, 589 
Right prismatic system, 179 
Rochelle salt, 436 
Rock salt, 448 
Rousseau's densimeter, 58 



OABADINE, 640 
O Sabadinine, 640 
Sabadilline, 640 
Saccharic acid, 570 
Saccharides. 561 
Saccharoses, 568 
Saccharum, 568 

lactis, 569 
Safety tubes, 161 

valve, Wislicenus, 144 
Safrene, 603 
Safrol, 603, 604 
Salicin, 647 
Sali cy amide, 614 
Salicylic acid, 613 
Salinaphtol, 560 
Saliphen, 614 
Salipyrine, 614 
Salol, 614 

coating for pills, 329 
Salophen, 614 
Sal prunelle, 438 

Seignette, 437 
Salt, Epsom, 480 

Everitt's, 609 



Salt, Glauber's 453 

Rochelle, 436 

rock, 448 

Schlippe's, 525 
Saltpetre, 438 

Chili, 449 
Salts, effervescent, 366 
Salumin, 615 
Santalal, 603 
Santalol, 603 
Santonin, 647 
Sapo, 594 

kalinus, 594 

mollis, 594 
Saponification, 592 
Saturated solutions, 112 
Scales, hand, 33 

prescription box, 35 

torsion counter, 37 

Troemner dispensing, 35 
Scammonin, 606 
Schaefer's test, 638 
Scheele's hydrocyanic acid, 610 

test, 610 
Schlippe's salt, 525 
Schweitzer's reagent, 546 
Separation of non- volatile matter, 132 

of volatile matter, 154 
Separators, 145 

centrifugal, 151 
Sesame oil, 195 
Sesquiterpenes, 202, 597 
Sifter and mixer, 103 
Sifting, 101 
Silver cyanide, 542 

iodide, 543 

nitrate, 543 

diluted, 543 
moulded, 544 

oxide, 544 
Simple solutions, 211 
Sinalbin, 601 
Sinigrin, 601 
Siphons, 147 

Smedley pill-compressor, 346 
Soap, white Castile, 594 

green, 594 

hard, 594 

lead, 594 

marine, 593 

soft, 594 
Soaps, medicated, 593 

official, 594 

superfatted, 593 
Socaloin, 645, 646 
Soda, 442 

by lime, 442 

caustic, 442 

chlorinated, solution, 455 

solution, 455 

tartarata, 437 
Sodii acetas, 442 

arsenas, 442 



INDEX. 



673 



Sodii benzoas, 442 
bicarbonas. 442 
bisulphis, 442 
boras, 442 
bromidnm, 442 
carbonas, 442 

exsiccatus, 442 
chloras, 442 
chloridum, 442 
hypophosphis, 442 
hyposulphis, 442 
iodidum, 442 
nitras, 442 
nitris, 442 
phosphas, 442 
pyrophosphas, 442 
salicylas, 442 
sulphas, 442 
sulphis, 442 
sulphocarbolas, 442 
Sodium acetate, 443 
arsenate, 443 

solution, 528 
benzenemetadisulphonate, 556 
benzenesulphonate, 558 
benzoate, 444 
biborate, 445 
bicarbonate, 444 

troches, 343 
bisulphite, 445 
borate, 445 
bromide, 446 
carbonate, 446 

dried, 447 
chlorate, 448 
chloride, 448 
citrate, 456 
ethylate, 457 
ethylsulphate, 457 
hydroxide, 442 
hypophosphite, 448 
hyposulphite, 454 
iodide, 448 
meta-antimonate, 524 
napthol, 560 
nitrate, 449 
nitrite, 449 

paraphenolsulphonate, 453 
phenol, 557 
phosphate, 451 

dried, 451 

effervescent, 452 
pyro-arsenate, 524 
pyro-borate, 445 
pyro-phosphate, 452 
resorcin, 557 
salicylate, 452 
santoninate, 457 
silicate, solution, 456 
sulphate, 452 

dried, 453 

effervescent, 453 
sulphite, 453 



Sodium sulphoantimonate, 525 
sulphoantimonite, 525 
sulphocarbolate, 453 
sulphovinate, 457 
tartrate, 457 
tetraborate, 445 
thiosulphate, 454 
valerianate, 457 
Solubility, determination of, 110 

lysimeter for, 111 
Solution, 108 

aluminum acetate, 484 
ammonia, 465 

caustic, 465 
ammonium acetate, 466 
arsenic and mercuric iodide, 527 
arsenous acid, 527 
Barfoed's, 567 
chemical, 108 
chlorinated potassa, 456 

soda, 455 
complex, 108 
Donovan's, 211, 527 
Fehling's, 567 
ferric acetate, 502 

chloride, 503 

citrate, 503 

nitrate, 504 

subsulphate, 504 

sulphate, 505 
Fowlers, 212, 528 
hydrogen dioxide, 405 
iodine, compound, 412 
iron albuminate, 509 

and ammonium acetate, 505 
Koppeschaar's, 558 
Labarraque's, 212 
lead subacetate, 533, 536 
lime, 475 

saccharated, 476 
Lugol's, 211, 412 
Magendie's, 633 
magnesium citrate, 480 
Mayer's. 622 
mercuric nitrate, 520 
Monsel's, 212. 505 
morphine bimeconate, 643 
Pearson's, 529 
potassa, 439 
potassium arsenite, 528 

citrate, 440 
simple, 108 
soda, 455 
sodium arsenate, 528 

silicate, 456 
Solutions, chemical, 211 
percentage, 114 
saturated, 112 
simple, 211 
supersaturated, 112 
Solvents, 115 
Somnal, 584 
Sorbinose, 566 



43 



674 



INDEX. 



Sorghum, 568 
Sozoiodol, 586 
Sozoiodolic acid, 586 
Sparteine sulphate, 638 
Specific gravity, 45 

adjustment by volume, 63, 64 

by weight, 64, 65 
areometers, 53 
areo-pycnometer, 58 
balance, Mohr's, 51 

Westphal, 51 
beads, Lovi's, 52 
bottle, 47, 49 
cylinder loaded, 50 
densimeter, Kousseau's, 58 
glass or metal plummet, 50 
Grauer's method for determin- 
ing, 50 
hydrometers, 53-57 
Baume, 55 

rules for, 55 
double, 56 
Nicholson's, 56 
spirit, 57 
Twaddell's 56 
liquids, 46 
solids, 59 

graduated cylinder for, 60 
in powder, 62 
methods of finding, 60, 61 
urinometer and cylinder, 58 
water, table, 48 
volume, 62 
Spermaceti, 192, 589 
Spirit ammonia, 238, 240, 461, 466 
aromatic, 238, 240, 461, 466 
anise, 238 
bitter almond, 238 
camphor, 238 
chloroform, 238 
cinnamon, 238 
cologne, 573 
ether, 238, 239 
gaultheria, 239 
glonoin, 239 
hartshorn, 465 
juniper, 239 

compound, 239 
lavender, 239 
lemon, 239 
myrcia, 239 
nitroglycerin, 239 
nitrous ether, 238, 239, 577 
nutmeg, 239 
orange, 238 

compound, 238 
"peppermint, 239 
phosphorus, 238, 240 
proof, 574 
spearmint, 239 
Spirits, 238 

official, 238 
Spiritus setheris, 238 



Spiritus setheris compositus, 238, 239 
nitrosi, 238, 239 
ammonia?, 238, 240, 461 

aromaticus, 238, 240, 461 
amygdalae amarse, 238 
anisi, 238 
aurantii, 238 

compositus, 238 
camphorse, 238 
chloroformi, 238 
cinnamomi, 238 
frumenti, 239, 240 
gaultherise, 239 
glonoini, 239 
juniperi, 239 

compositus, 239 
lavandulse, 239 
limonis, 239 
menthse piperita?, 239 

viridis, 239 
myrcia;, 239 
myristicse, 239 
phosphori, 239, 240 
vini gallici, 239, 240 
Square prismatic system, 178 
Starch, 561 
corn, 564 
glycerite of, 564 
official, 564 
moss, 563 
potato, 563 
soluble, 562 
Steam press for fixed oils, 188 
Steapsin, 650 
Stearin, 190, 588 

Stibium sulphuratnm aurantiacum, 525 
Still, Anderson's, 167 
Beck's, 165 
copper, 169 
Remington, 166 
Eice's, 170 
Stills, 165 

automatic, 169 
dreg, 171 
vacuum, 172 
Strainers, 133 
Straining, 132 

Straw rings for supporting dishes, 156 
Strontii bromidum, 469 
iodidum, 469 
lactas, 469 
Strontium bromide, 476 
iodide, 476 
lactate, 477 
Strychnine, 639 

sulphate, 640 
Sublimation, 175 
Sucrose, 568 
Suet, 588 
Sugar, beet, 558 
cane, 568 
coating for pills, 379 



INDEX. 



675 



Sugar, grape, 56(5 

inverted, 563, 567 

malt, 568, 570 

milk, 568, 570 

peat, 573 

raw, 568 
Sulphaminol, 586 
Sulphonal, 587 
Sulpho-oleates, 592 
Sulphur, 414 

flowers, 414 

iodide, 415 

liver, 430 

lotum, 414 

milk, 415 

of antimony, golden, 525 

precipitated, 415 

sublimed, 414 

washed, 414 
Sulphurated antimony, 525 
Sulphuretted oils, 203 
Summary of incompatibilities, 303 
Supersaturated solutions, 112 
Suppository box, 401 

compressor, Genese, 396 

machine, Archibald's, 394 
Whitall's, 395 

mould, Blackmann, 394 
Maris's, 393 
See's, 394 

"The Perfection," 395 
Wirz's, 395 

shells, cacao-butter, 400 
gelatin, 400 
tinfoil, 400 
Suppositories, 389 

glvcerin, 398 

rectal, 390 

vaginal, 390 

Wellcome-shape, 390 
Sylvestrene, 202, 597 
Syrup acacia, 223 

almond, 221 

althaea, 224 

blackberry, 227 

calcium lactophosphate, 224, 469 

citric acid, 221 

ferrous iodide, 224, 492 
. garlic, 223 

ginger, 223 

hydnodic acid, 223,412 

hypophosphites, 225 
with iron, 225 

iodide of iron, tasteless, 510 

ipecac, 225 

iron arsenate, 510 
citro-iodide, 510 
soluble oxide, 510 

krameria, 225 

lactucarium, 225 

lime. 224, 469, 4V5 

official, 221, 568 

orange, 221 



Syrup orange flowers, 221 
orgeat, 221 

phosphates iron, quinine, and strych- 
nine, 225 
raspberry, 221 
rhubarb, 226 

aromatic (spiced), 226 
rose, 227 
rubus, 227 

sarsaparilla, compound, 227 
senega, 228 
senna, 228 
simple, 221 
squill, 227 

compound. 227 
tar, 226 
tolu, 222 
wild cherry, 226 
Syrups, 218 

flavoring, 221 
medicated, 223 
official, 220 
preparation, 218 
preservation, 220 
Syrupus, 221 
acaciae, 223 
acidi citrici. 221 

hydriodici, 223 
allii, 223 
althaea?, 224 
amygdalae, 221 
aurantii, 221 

florum, 221 
calcii lactophosphatis, 224, 469 
calcis, 224, 469 
ferri iodidi, 224, 492 

quinina? et strychnina? phos- 
phatum, 225 
hypophosphitum, 225 

cum ferro, 225 
ipecacuanha?, 225 
krameriae, 225 
lactucarii, 225 
picis liquidae, 226 
pruni virginianae, 226 
rhei, 226 

aromaticus, 226 
rosae, 227 
rubi, 227 

idaei, 221 
sarsaparilla? compositus, 227 
scillae, 227 

compositus, 227 
senegae, 228 
sennae, 22S 
tolutanus, 222 
zingiberis, 223 



^ABLE, comparative, metric and apoth- 
ecaries' fluid measures, 31 
metric with avoirdupois and 
apothecaries' weight, 30 



676 



INDEX. 



Table of different national Pharmaco- 
poeias, 17 

of official tinctures arranged accord- 
ing to strength, 246 

of the specific gravity of water as ob- 
served at different temperatures, 48 

of the volume of one pound in dif- 
ferent liquids of official quality, 27 

showing the number of drops in a 
fluid drachm, 43 
Tables of metrical measures, 28, 29 
Tablet-compressor, the Oriole, 348 

-saturates, 353 

-triturate mould, 351 
Colton's, 352 

-triturates, 349 
Tablets, hypodermic, 353 
Tannin, 615, 616 
Tar, 553 

birch, 598 

coal, derivatives, 555 
Tartar, cream of, 432 

crude, 432 

emetic, 523 

salt of, 434 
Tartrated antimony, 523 
Tartarus boraxatus, 433 

natronatus, 437 

stibiatus, 523 
Teel oil, 195 
Tenaculum, 134 
Terebene, 605 
Terpenes, 202, 597 
Terpineol, 599, 606 
Terpin hydrate, 604, 605 
Tessular system, 177 
Test, Boettger's 567 

Hubl's iodine, 591 

Kerner's, 637 

Moore's, 567 

Schaefer's, 638 

Scheele's, 610 

Trommer's, 567 
Tetragonal system, 178 
Tetronal, 587 
Thalleioquin, 638 
Thermostats, 77 
Thiosinamine, 602 
Three Samsons of medicine, 528 
Thymol, 603, 606 
Tinctura aconiti, 243, 247 

aloes, 243, 247 

et myrrhse, 243 

arnica? florum, 243, 247 
radicis, 243 

asafcetida?, 245, 247 

aurantii amari, 243 
dulcis, 243, 247 
adonna? fo' 

benzoini, 245 

composita, 245, 247 

bryonia?, 243, 247 

calendula?, 243 



Tinctura calumbse, 243 

cannabis Indiea?, 243, 247 
cantharidis, 243 
capsici, 243 
cardamomi, 243 

composita, 243 
catechu composita, 243 
chirata?, 243 
cimicifuga?, 243 
cinchona?, 243 

composita, 243 
cinnamomi, 243, 248 
colchici seminis, 243 
croci, 243 
cubeba?, 243 
digitalis, 243 
ferri chloridi, 244, 248 
galla?, 243, 248 
gelsemii, 243 
gentiana? composita, 243 
guaiaci, 245 

ammoniata, 245 
herbarum recentium, 245, 248 
humuli, 243 
hydrastis, 243 
hyoscyami, 243 
ipecacuanha? et opii, 244, 248 
iodi, 244 
kino, 245, 248 
krameria?, 243 
lactucarii, 243, 248 
lavandula? composita, 244 
lobelia?, 244 
matico, 244 
moschi, 245, 248 
myrrha?, 245 
nucis vomica?, 244, 249 
opii, 244, 249 

camphorata, 245 

deodorati, 244, 249 
physostigmatis, 244, 250 
pyrethri, 244 
quassia?, 244, 250 
quillaja?, 245, 250 
rhei, 244 

aromatica, 244 

dulcis, 244 
sanguinaria?, 244, 250 
scilla?, 244 
serpentaria?, 244 
stramonii seminis, 244 
strophanthi, 244, 250 
sumbul, 244 
tolutana, 245 
Valeriana?, 244 

ammoniata, 244 
vanilla?, 244 
veratri viridis, 244 
zingiberis, 244 
Tinture aconite, 243, 247 

Fleming's, 247 
aloes, 243, 247 

and myrrh, 243 



INDEX. 



677 



Tincture arnica flowers, 243, 247 

root, 243 
asafetida, 245, 247 
belladonna leaves, 244 
benzoin, 245 

compound, 245, 247 
bitter orange peel, 243 
bryony, 243, 247 
calabar bean, 250 
calendula, 243 
calumba, 243 
cantharides, 243 
capsicum, 243 
cardamom, 243 

compound, 243 
catechu, 243 

compound, 243 
chirata, 243 
cimicifuga, 243 
cinchona, 243 

compound, 243 
cinnamon, 243, 248 
colchicum seed, 243 
cubeb, 243 
digitalis, 243 

ferric chloride, 244, 248, 506 
gelsemium, 243 
gentian, 243 

compound, 244 
ginger, 244 
guaiac, 245 

ammoniated, 245 
hops, 243 
hydrastis, 243 
hyoscyamus, 243 
ipecac and opium, 244, 248 
iodine, 244 

Churchill's, 412 

decolorized. 412 
iron citrochloride, 510 

tasteless, 510 
kino, 245, 248 
krameria, 243 
lactucarium, 243, 248 
lavender, compound, 244 
lobelia, 244 
matico, 244 
musk, 244, 248 
myrrh, 245 
nutgall, 243, 248 
nux vomica, 244, 249 
opium, 244, 249 

camphorated, 245 

deodorized, 244, 249 
phosphorus, 239 
physostigma, 244, 250 
press, 149 
pvrethrum, 244 
quassia, 244, 250 
quillaja, 245, 250 
rhubarb, 244 

aromatic, 244 

sweet, 244 



Tincture saffron, 243 

sanguinaria, 244, 250 

serpentaria, 244 

squill, 244 

stramonium seed, 244 

strophanthus, 244, 250 

sumbul, 244 

sweet orange peel, 243, 247 

tolu, 245 

valerian, 244 

ammoniated, 244 

vanilla, 244 

veratrum viride, 244 
Tinctures, 241 

made by decoction, 245 
maceration, 245 
percolation, 243 
solution, 244, 246 

official, 243, 246 

of fresh herbs, 248 
Tolu-coating for pills, 327 
Toluene,' 555 
Torrefaction, 158 
Tragacanth, 564 
Trehalose, 568 
Triacontan, 598, 600 
Tribromomethane, 583 
Tribromophenol, 558 
i Tricalcium phosphate, 472 
Trichlormethane, 583 
1 Triclinic system, 181 
Trimethylamine, 589 
i Trimethylxanthine, 627 
Trimetric system, 179 
Trimorphous crvstals, 176 
Trinitrin, 595 
Trional, 587 
Trisodium arsenate, 444 
Trituration of elaterin, 365 
Triturations, 365 
Troches^ 336 _ 
Trochisci acidi tannici, 342 

ammonii chloridi, 342, 461 

catechu, 342 

cretse, 342, 469 

cubebse, 342 

ferri, 342, 487 

glycyrrhizse et opii, 342 

ipecacuanha?, 342 

krameriae, 342 

menthae piperita?, 342 

morphime et ipecacuanha?, 342 

potassii chloratis, 343, 429 

santonini, 343 

sodii bicarbonatis, 343, 442 

zingiberis, 343 
True weight, 24 
Truxilline, 629 
Trypsin, 650 

Tubulated retort and flask receiver, 161 
Turpeth mineral, 520 
Tutia, 539 
Tutty, 539 



678 



INDEX. 



TTNGUENTUM, 373 
U acidi carbolici, 376 

tannici, 376 

aquse rosse, 373 

belladonna?, 376 

caseini, 372 

chrysarobini, 376 

diachylon, 373 

gallse, 376 

hydrargyri, 376, 513 

ammoniati, 376, 513 
nitratis, 377, 513 
oxidi flavi, 376, 513 
rubri, 376, 513 

iodi, 376 

iodoformi, 376 

picis liquidse, 373 

plumbi carbonatis, 376, 533 
iodidi, 376, 533 

potassii iodidi, 376 

stramonii, 376 

sulphuris, 376 

veratrini, 376 

zinci oxidi, 376, 533 
Ural, 584 
Uralium, 584 
Urethane, 586 



yALERALDEHYDE, 602 
y Vegetable jelly, 565 
Veratrine, 640 
Veratroidine, 640 
Vessels for crystallization, 184 
Viel's capsulator, 327 
Vinegar opium, 254 
squill, 254 
wood, 549 
Vinegars, 253 

official, 254 
Vinum antimonii, 253, 522 
colchici radicis, 253 

seminis, 253 
ergotse, 253 
ferri amarum, 253, 487 

citratis, 253, 487 
ipecacuanhas, 253 
opii, 253 
Vitriol, blue, 533 

elixir, 427 
Volatile oils, 196 

chemical composition, 597 
classification, 202 
distillation, 198 
expression, 200 
extraction, 201 
official, 598 

pneumatic methods for obtain- 
ing, 201 
Volume of one pound in various liquids 
(table), 27 



WATER, 405 
ammonia, 207, 464 
stronger, 207, 465 

anise, 208 

bitter almond, 207 

camphor, 208 

chlorine, 207, 408 

chloroform, 207 

cinnamon, 208 

creosote, 207 

distilled, 208 

fennel, 208 

interstitial, 183 

lead, 211, 537 % 

of crystallization, 183 
decrepitation, 183 

orange flower, 207 

stronger, 208 

peppermint, 208 

spearmint, 208 

rose, 207 

stronger, 208 

-still, Curran's, 209 
Waters, aromatic, 208 

medicated, 206 

official, 207, 208 
Wax, earth, 596 

mineral, 596 

white, 191 

yellow, 191 
Weighing, rules for, 39 
Weight, apothecaries', 25 

avoirdupois, 24 

gross, 39 

imperial, 24, 26 

metric, 27 

net, 39 

standards, 25 

symbols, 25 

tare, 39 

troy, 24 
Weights, aluminum, 39 

and measures, 24 

apothecaries', 38 

block, 38 

cup, 38 

metric prescription, 39 
White, nothing, 539 

precipitate, 515 
Wine antimony, 253, 522 

colchicum root, 253 
seed, 253 

ergot, 253 

ipecac, 253 

iron, bitter, 253 

iron citrate, 253 

opium, 253 

red, 251 

white, 251 
Wines, 251 

detannating, 251 

medicated, 252 

official, 253 



INDEX. 



679 



Wood alcohol, 549, 552 

naphtha, 552 

vinegar, 549 
Wool-fat, hydrous, 191 

ZINC acetate, 537 
bromide, 537 

carbonate, precipitated, 538 
chloride, 538 

solution, 540 
flowers, 539 
hypophosphite, 541 
iodide, 539 
lactate, 541 
ointment, 376, 533 
oleate, 384, 533 
oxide, 539 



Zinc phosphate, 541 

phosphide, 539 

salicylate, 541 

sulphate, 540 

sulphocarbolate, 541 

valerianate, 540 
Zinci acetas, 533 

bromidum, 533 

carbonas prsecipitatus, 533 

chloridum, 533 

flores, 539 

iodidum, 533 

oleatum, 533 

oxiduru, 533 

phosphidum, 533 

sulphas, 533 

valerianas, 533 



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